Germán Montoya Sanhueza
Biologist, interested in processes of morphological change in mammals. Currently studying skeletal biology of subterranean African molerats at the University of Cape Town, South Africa.
Location from Chile
Activity
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yes, interesting thing about the volition implication. This implies that only humans have conscious goals?? who define those concepts?? so feeding, replication or walking doesn't have a goals? they have roles? ;)
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@DavidLillystone Hi David, I'm convinced that we agree in general in this discussion. Our disagreement is a fact of definitions only. Genes (not evolution) have a specific goal, since they are molecules, structures, a system. The action (function) of a gene it is its goal, like the heart has a function, and the legs and blood have a function as well. Genes are...
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Hi Ian, interesting questions! First than all, all species evolve, in a daily basis. These questions are biased to our -cultural- conceptions of intelligence and technology though. Intelligence is not only the process of knowing something, have information, or knowing a lot. It also involves development of cognitive systems (structures and function), as well...
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@DavidLillystone Hi everyone! Is great to see this interesting discussion! I was reading the comments from the beginning and I found that there are some confusions though (normal in discussions) about the goal or not goal of life, the directionality or randomness of genes/evolution. This may help. First, genes are not equal to evolution or vice versa....
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Yes, and also be informed of the specific goals, mechanisms and steps of the NGOs, many of them recollect resources and those are not used directly for the community...
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Exactly Chris, I think regardless the final end is, we just must do it, change behaviors, lifestyles, ideas and educate...doesnt matter if we will see the results in this o next generation. We are too selfish sometimes to do a change, because doesn't give us a reward individually...
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Hi Kiran, Not really, I think the idea (and human responsibility) is to learn, not to spread all over consuming resources as uncontrolled creatures. We have the cognitive capacity to be a "sustainable species", but we must use it ;)
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Hi B Johnson, the cones in the figures only represent TRENDS for increasing biodiversity (based on the known fossil record) during periods. Red lines indicate events of extinction, so the cones decreases their thicknesses just after the event, but they start to thicken with time.
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Germán Montoya Sanhueza replied to Patricia Hay
Hi Mark, it is difficult to give a final answer since only few species have been comprehensively studied in terms of speciation and microevolution, and clearly different species have different patterns of speciation. Have a look of the general trends here: https://evolution3e.sinauer.com/summary18.html
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yes! but have in mind that in the past there were not huge industrialization and high emissions of CO2 to the atmosphere, so the quantity of CO2 able to be absorbed by forests has changed drastically by human effect. We will see it further in the course...
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Hi Onelia! Current research in geochemistry of soils and gas interchange between atmosphere and plants have suggested that forests work as deposits of carbon (look for CO2 and forests), so plants are definitely our friends to ameliorate climate change today.
However, what this video explain is that the increase in nutrients and minerals in the oceans as a... -
Hi Kiera! yes, it is probable and it does not mean that is a rule or exclusive events, or that re-population (or radiation/diversification) wont happen as well. Different groups of organisms have different rates of differentiation, even within the same groups, e.g. mammals. Some of them diversify quite fast whilst others don't.
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Hi Margaret, the estimations of disappeared species are usually based on the total number of fossils species found in a defined period (not total number of species of that period, that is impossible to know, and estimations would be too speculative).
It is difficult to know if these "few" million years separating these two events represent different processes... -
Hi Ron! I think the answers to your questions may not be quite clear cut. It is unknown and unlikely that the only factor contributing to conquer of land habitat by fish is related to "the search" for oxygen. Remember, it was only a group of fish, not all fishes, conquering the land. If all fishes would "look" for oxygen, then it wouldn't be any fish left in...
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Hi Debbie! sorry but humans we never had gills ;) During embryonic development we go under several transformations, and one of these is the opening of branchial or pharingeal archs, which "looks" like gills, but they never develop or work as a proper gill. But, yes, these structures are related to the development of gills in fish and amphibians. Cheers
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Germán Montoya Sanhueza replied to Stuart Holding
Hi Stuart! I'm not sure if I got your questions properly, but here it goes: It has been proposed that the interior of Pangea was quite dry, especially because around this huge landmass, extensive mountain chains were developed, thus limiting the flow of air currents and rainfall towards the center. This mountain blocking geomorphology (causing rain shadow...
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Germán Montoya Sanhueza replied to Patricia Hay
Hi Patricia, I think that is incorrect: "...in the wild will not accept an animal that is too different from the rest of the pack". Animals do not accept other individuals because their strategy to survive is to protect the pack were they grew up, not because the new individual is too different (a foreigner is a foreigner, even if is part of the same species -...
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Hi Patricia! it is tricky to know if there was a transitional egg between these two phases, since a transitional phase would be likely not completely mineralized and the fossil record hardly preserves soft tissues and even eggs. But it is expected that during the evolution of animals from aquatic to terrestrial environments, should appear several events of...
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Ron Duke, that is not realistic at all, and is also encouraging the abandonment of the idea of human responsibility, which we must have with our lifestyle...Also embraces the idea of the next colony, the next migration, instead of learning to live in a sustainable way. Dispersion and colonization cant be anymore a reasonable option for "human survival", at...
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Hola Jessica! No worries, there are no fool questions in this platform...It is a tricky question but certainly some extinctions can be predicted, while others cant. It depends on what species is being affected and what is the cause of their extinction (or threat). Stochastic (sudden) events such as meteorite impacts, massive floods, cold periods or droughts...
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Stuart James, all the contrary, we need to worry about! and that is one of the changes we need to do, a view of the future as part of our lives, even if we wont be here. Cheers!
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Thanks Eileen!! That is one of the amazing parts of paleontology, always there are new news from the past. Enjoy the course!
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Hi Catherine! this may be possibly true...certain species live longer as a "discrete" group of individuals, while others may have high rates of mutation (=genetic change), making the population different and thus generating "new" species...anyways, species will have an "expiration date" depending on genetic and external (environmental and ecological) factors....
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Hi Teresa! your comment remind me of this book, or maybe you know it already...can be interesting for you.
https://www.goodreads.com/book/show/20696006-being-mortal
Enjoy our course! -
Hi Patrick, you can download the transcript of each class by clicking just below each video, as well as you can download the videos. Im not sure if that is what you referring to?
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Hi Rwth! it is a tricky question and clearly under a biological and ecological point of view there is not clear cut answer. Species have different strategies to deal with food resources, and as you said, in general they "will" adjust their populations to the existing conditions, for instance migrating, eating less, changing diet, increasing depredation, etc....
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Hi Bryan, what you are describing is called Human Diversity, not everyone has the same behavior, even for the same situation (thankfully). Learning to understand this fact, will help us to solve many of our frictions as society.
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Hola Tomasa! los "browsers" son los animales que comen de las ramas de los arboles/arbustos, ramoneando, por eso se denominan ramoneadores. Los animales que comen de pastos en el suelo se llaman pacedores (ellos pacen). Es toda una terminologia generalista enfocada a describir estilos de estrategia alimentaria. Saludos!!
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hey guys! mammals appeared before dinosaurs! but they were not as diverse as we see today, actually for a long time, during most of the Jurassic and Mesozoic they were small animals, occupying different environments but not being the most common large vertebrate on land....just after dinosaur extinction (during the Paleocene) they started to diversify in to...
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yes that is correct!! good summary ;)...and yes, Jurassic Park has many ambiguities, unfortunately.
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Hi Astrid and Marisa....the dates are correct, after the Triassic extinction comes the Jurassic period, and just after this comes the Cretaceous....so i think the confusion was to think that after Triassic the Cretaceous was next, that is wrong. Please see the following link with chart and keep it thru all the course for reference ;)...
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Germán Montoya Sanhueza replied to Jana Renda
there are different questions: 1) is this planet able to support life without tectonics? yes, but for how long? and 2) is the origin of life related to the dynamics of plate tectonics? Strictly probably not, but is it related to the activity of inner earth?
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communities, cities, governments should focus in long term projects of sustainability, education and communication with our kids is essential.
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Yes, day to day scientists are understanding that processes are not cleat cut, nor unidirectional, instead there is a complex interrelationship between variables and factors...different analytical tools, specially mathematics and statistics help to measure the weight or contribution of a set of variables in to a determined system.
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it is possible to find such evidence, but is unlikely to be recorded...some bacteria/viruses can have effects on soft and hard tissues, so if you analyzed bone tissues you may find pathological structures.
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not quite, since bacteria and viruses may cause the death of certain populations and species but hardly affect the complete ecosystem. However, the extinction of one group can have strong consequences in others....chain effect.
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interesting too! what is the relationship of environment and body armors?...but remember that many animals living in conditions (ecological or environmental) requiring an armor do not develop them...so also may be a phylogenetic pattern (inheritance).
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is called guadalupian extinction because the time when it happened is stratigraphically denominated Guadalupian. So many events in life history are called by the time when they occurred. You can see a chart of geological time and all its periods and ages here: http://www.stratigraphy.org/index.php/ics-chart-timescale
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thanks for the correction! Clararia is fine though, Clavaria is a fungus genus.
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Malcolm also said it ;)
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Hi people! you have to have in mind that the tectonic dynamics is basically like a hot boiling liquid (magma) with a solid cold external surface (the Earth's crust), and depending on the thickness of this crust and the hotness of the magma the different land masses move around or in certain directions...clearly is not something we can see in our life span, but...
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Hi Jorge, this species has been widespread in cultivation for several centuries, so in that sense "is not endangered", because you can find it in several countries around the world... But actually, its original habitat and their population is actually Endangered...please find more info for this and other species of the world in the following link:...
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it is true!! but also keep in mind that there is not such thing as a GOAL or FINAL POINT in evolution...so when you say "there were many early versions of humans", that is simply not accurate (it seems for us -HUMANS- but it doesnt!!). We are just a result of the conditions, we never were planned to be like this. This conflict happen because we tend to trace a...
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guys! remember that an egg is quite analogous to a cell (having a nucleus and membrane)! and life started with unicellular microorganisms ;)
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Dont forget to look other animal forms guys....life strategies are even more variable when we observe mollusks and arthropods, which constitute most of the fauna in this planet and are crucial to sustent all vertebrate life as well!!
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I think the concept of dominating species can be misunderstood...in this case it just means that they were just abundant or succesful to cope with specific external conditions, but it doesnt implies any kind of special interaction over other species. The term "prolific" also doesnt mean better. Environments are also quite variable and in some habitats a...
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Hi Astrid, there is not specific differences between those names, since they usually refer to common names for unicellular organisms (life). In Greek, Micro- it means "small" , and Bios- it means "life".
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Hi Dave, this is an interesting question! but unfortunately doesnt have an unique answer...as Barbara's example, the presence of an armor in vertebrates can have different functions (e.g. usually protection), and actually in the case of early fish, there is no final agreement among researchers about the functionality of the armor, but it may be developed as...
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Hi Melanie! In addition to Anusuya's comment, i) yes, some components of the "Edicaran biota" went extinct around 540 mya, since they are not preserved in other younger strata. ii) However, their fossil record is geographically and taphonomically limited, so it is difficult to say they were once a widespread and representative group. iii) They also coexisted...
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Bienvenida Romina! We hope you enjoy this course. It has several sections were you can find interesting information about paleontology and geology, as well as ecosystem conservation. Just let us know if you have any question! GM
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Germán Montoya Sanhueza replied to Jack Gray
Sorry Jack, plesiosaurs were not dinosarus, but they were contemporaneous.
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I liked that "theory that we are intelligent"....not quite.
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Hi Leslea! this is a nice question! it is true, plants move much less than animals, but they do not adapt less at all!! Plants have amazing systems of evolution and adaptation. One of them is called phenotypic plasticity, which is a mechanism of morphological or physiological change occuring during the life of the individual that permits them to face new...
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Carlos, the World is not designed for the prevailance of predators at all! the biomass of plant communities is immensely huge when compared to predators! if that is what you mean.
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Hi Molly! of course you can see the changes! it just depends of where you put your attention (nations, villages, family, friends, etc). Education and transferring knowledge and experience is one of the most valuable things that "oldies", as you say, can do!!
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yes Joseph, and this happen with many terms in science, i.e. terminology it doesn't start in a specific day and finish in another one. But the sense of calling this epoch as Anthropocene is quite evident; the changes that humanity has produced have not equivalent in previous epochs, e.g. plastic was not before us! and now all the aquatic systems and seas have...
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One of the goals of this course is to integrate several aspects of scientific knowledge (e.g. biological, geological, palaeontological) to understand prehistorical (and historical) processes. Science is not isolated, it is done by people, and we live in a society where good and bad decisions (politics) are contributing to many of the processes we are seeing...
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This is a very interesting but still unsolved question. Ingestion, as you said below, is apart of every animal. You don't need teeth to get nutrients, but there are hierarchical levels of depredation and clearly teeth has evolved in many ways to maximize foraging and nutrition. It is amazing how the big sauropods (long neck dinosaurs), the largest terrestrial...
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Omnivorous animals can be classified as generalists and in general these animals are less susceptible to be affected by environmental changes. Someone said it before in the comments, the more specific you are, more vulnerable you are to survive. I like how biology can be connected with sociology....How this relates to our mind? as more socially tolerant we...
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I see you are doing the right questions! you should be in a lab doing all these testings and experiments!!! Unfortunately, there is not unique answer, and biological and biochemical processes are likely to be generated multiple times....what can we conclude from this?
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hi there! returning to Jean's question, only eukarya have organels such as mitochondria and chloroplasts (surrounded by a membrane). Bacteria and Archaea doesnt have organels within them, but it has been hypothesized that bacteria has ended within other cells to finally produce an eukaryote.
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Hola from Chile!
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No worries Penelope! to memorize the dates is not the most important thing, but appreciate the proportions of time when life occurred and where we are situated!
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haha fascinating! equal generational transfer of information is so important!!
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Good conclusion, actually one of the fundamentals!
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learning about the past, and then the present is the best predictor of the future...
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yes totally! viruses are carriers of genetic material and hence are hypothesized to influence early life as they do today, please see Horizontal gene transfer http://www.panspermia.org/virus.htm
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glad you liked Peter! nice to see how you guys enjoy this course! :)
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Gordon, is not true that we are living in the most biodiversified period of Earth's life.
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Yes, but we can see today that certain organisms are able to diversify quite quickly in certain regions (habitats). Look for the example the evolution of cichlids (a type of fish), http://news.stanford.edu/news/2014/september/fish-genome-fernald-092214.html
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Your questions is interesting Lee. The niche is an ecological concept to define the use of resources and space by a group organisms or individuals. Not all organisms have the same niche, but they can overlap some features of their niche, e.g. use of water, use of trees for nests, etc. So when dinosaur were wiped out, many habitats were able top be used by...
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Thanks!! it is much appreciated that you liked the content, graphics and charts!! You can also refer to Anusuya's book, https://www.amazon.com/Indigenous-Knowledge-Library-Fossils-Africa/dp/1107610052
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Hi Roger, the book from SJ Gould "Wonderful Life" is a totally recommended!!
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yes Robin, the book from SJ Gould "Wonderful Life" is a good book to have a beautiful insight from life in that period!! totally recommended!!
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Do you mean in the fossil record? At those huge timescales we cant have evidence of this process, since (micro)organisms do not preserve such fine structure during fossilization.
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Good points! symbiosis and interaction are key phenomena in life and evolution. This is quite interesting in my personal view to understand the relevance of human interaction and cooperation among societies ;)
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Germán Montoya Sanhueza replied to Janet P
hahaha good one Janet...some societies need more colorful excuses to do science! :(
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sure we are!
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Nop, these are not stromatolites, but other signs of microbial life. Stromatolites form large sedimentary structures since they live in aggregations of millions of microorganisms.
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Hi Francis, it is usually assumed in paleontology that the fossil (organism) is synchronous (same age) to the sediment deposition which formed the rock. But it is true, sometimes a sediment can preserve an organism but it does not mean that the rock was formed at the same time, it may take longer. There is variation, and we are dealing with estimations, not an...
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life is not fragile, species, populations, communities and ecosystems are!
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yes and not. Even if we found evidence of life "in a meteorite", it does not excludes the possibility that life (as we know it) originated in the Earth. It is known that many biological processes arise more than once in different groups, so we cannot close our minds to believe that life originated only once at universal scale. In the past, people thought that...
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yes Leslea! ambar containing signs of life from the past is also a fossil. This has to be corroborated by dating the (radiometric) age of the rock (or substrate) where the fossil is embedded. Archaeological remains are not considered fossils though, since those have not been under strong tectonic compaction and geo-chemical transformation. However, this is a...
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hey! returning to the original and interesting question, does evolution stagnates? probably not, but rather it shows different rates of speciation and diversification, which it depends on the group that we are observing, e.g. bacteria vs birds. These groups will have different patterns of evolution, but hardly evolution stops, since the purpose of life...
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yes! we have to think that the fossil record is BIASED. It does not show us the total number of species, and not even all the types of organisms that once existed. It is probably that in the first couple of thousand billion years, not all life was able to be preserved. Likewise, it is likely that the process of fossilization was not as intense as it was later...
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I think this is a good point, why the 6th extinction is not a natural event, as already happened before? We will see in the next weeks how there is so much information about higher rates of species decline and extinction during a short period of time (historical). We also have to consider that our rise as humans has not equivalent in other species, especially...
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woow, this is a real debate about origin of life! we need creative people and discussions like this more often!! ....as part of our idiosyncrasy, since it allows us to question every aspect of our nature, organization and our relationships, both among species and within OUR species. Then we can realize that the original question is not any more the most...
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yes! that would be amazing, and it should be a common part of the school curriculum, for kids and more!!
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unfortunately not yet Sarah, but it should be! check this: http://barberton.co.za/geology/
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yes Rob, the oldest rocks with fossil evidence in Africa are about 3.5 Billion yo, you can find two articles of M. de Vit here http://www.sajs.co.za/sites/default/files/publications/pdf/277-1615-3-PB_0.pdf
https://www.geol.umd.edu/~kaufman/ppt/G436/G436_PDF_library/Furnes_04.pdf
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Hi Sarah and Amy! thank you very much for your good question. The cones in this chart are only a schematic representation of the dynamics of extinction and radiation of organisms during geological time (not to scale). To have an accurate visualization of these processes we should include the complete fossil record for each period (including plants AND...
