Evolution, Morphology and Exobiology

I look at the variety. Whales, seals, orcas, manatees...then the semi-aquatics like the hippos, etc. Can assume that at one time in earth's history, there was more water around, than there already is? Forcing these branches of mammals into the water? Or was it by choice, to get food, or safety from predators?

I've managed to get confused about terminology around evolution and am not sure I have it correct. Is a trait Homologous if all descendants from a common ancestor have it? Or do all members of the species have to have this trait? For the example I have in mind - human "hairlessness" (this misleading term referring to smaller hairs than related apes, not actual absence). All juvenile humans are "hairless" before puberty (except for head hair, which they also share in common) but adults vary from male to female (dimorphism) as well as vary across different populations. The hairless juvenile trait is universal within our species and is therefore homologous? But pa…

Hello,everyone I am new to this forum.My name is Konis and i have a question for you. I've had gynecomastia(male breast enlargement because of hormone imbalancement) for about 7 years now.The point that i could use medication has passed . The only solution that doctors reccommend is getting a surgery. But thats pretty expensive and insurance companies dont cover it.So i was thinking.. Is there a way to get rid of the fibrous tissue in my breasts?I know that since its formed it stays there.Could there be a chemical that i can apply or inject that would actually work?! The only thing i've tried is dmso with liwuid iodine but it doesnt seem to do much if anyth…

Why did some humans develop this?

just wondering, is it possible to predict evolution of a particular species? if we know the evolutionary history of that species and are aware of the factors that contributed to it. can scientists make accurate assumptions about the future of a species? for example, is it possible to predict the next stages in human evolution?

Is there a name for behaviors that are passed down for thousands or millions of years in insects or other animals that are no longer used or needed in todays environment? Can anyone give and example? Thank You!

Given that we have an environment with water, land and air, wasn't it inevitable we ended up with things swimming in water, walking on land and flying in the air? For example, evolution might produce random 'wing' designs but only the ones that are areodynamic will work, meaning wings have a certain inevitability.

Hello, ScienceForums, I made a list of Best Richard Dawkins books I think that all science lovers need to read. url deleted do you agree with the list? or should I add another books to the list? any suggestion is welcome.

Is there an expert chemist/Biologist in the house? Can someone detail the errors and/or nonsense in this blokes critique of Abiogenesis. He also has one supposedly refuting Evolution. His name is James Tour Yes he certainly has his share of religious baggage, as he is a fanatical "Messianic Jew" https://en.wikipedia.org/wiki/James_Tour#Religion What's one of them I hear someone ask? here..."Messianic Judaism[a] is a modern syncretic[1]religious movement that combines Christianity—most importantly, the belief that Jesus is the Hebrew messiah—with elements of Judaism and Jewish tradition.[2][3][4][5] It emerged in the 1960s and 1970s." The following is a vi…

I have been prompted to start this thread after a valid, logical statement I made in another thread, and which was foolishly and ignorantly I believe questioned by another member. Perhaps though I am being a touch too hard. Perhaps this is just another example of a brainwashed creationist/IDer inevitable argument and protest. Anyway to the subject of the thread......Is the claim I made thus.... "certainly we know that at one time there was no life [universally speaking] then there was" correct? My contention based on mainstream science is that Abiogenesis is the only scientific answer to how life first started in the universe. It certainly to the best of our knowle…

Hello ¡¡ I from am Colombia, sorry for my english, I am a Student of Engineering and with a companions ,we want to create a 3d model of plants simulating reality, our problem is that we do not know the name of the study or the specific science that specifies the number of branches, the number of leaves, the distance between the branches, the distance between leaves, the distribution between them, and everything that is related, because we need all the numerical data for the creation of our plant

What could be an evolutionary purpose to have digestive system strictly differentiated into the stomach, small intestine and large intestine? Is it too difficult to have a single organ which can perform the functions of all the three? For example something similar to a large intestine?

Any expert commentary to fully explain the following papers to me welcome and of course encouraged.........I certainly have heard about the "Miller/Urey experiment, mostly that it was inconclusive? What do the following papers say about that result, in simple language? https://www.ncbi.nlm.nih.gov/pubmed/26508401 Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth: Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers. Abstract: In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529…

Curious Christian here - I've been reading The God Delusion - I prefer not to comment, apparently I'm too stupid to understand anything because I'm a Christian. I've nearly finished chapter 4, and I have a question about the argument that evolution works because of a slow ascent of design. Examples given include the eye, where it begins with a very rudimentary semi-form of an eye, and then works its way up 1% of an eye, 2% and so on. No argument from me there, the problem not addressed is the progression from 0% to 0.0000001% of something. So far Richard's argument seems to solely be, "I'm not smart enough to understand this, an almighty God could not possibly be smarter …

I hear some people say it's a social construct.

Occasionally, I read about creatures that have remained relatively unchanged for a hundred million years or more. Does this mean they have stable DNA or is it due to some other factor?

Ponder that for a minute. To me that would explain the giantnormous diversity of humans to humans and species to other species. All living things. Especially since we know when DNA copies itself it makes errors..

How does sexual selection affect introverts?

There's an issue that's been bugging me since my early teens and which now, at 39, I would like to put to rest. I think I have long figured out the answer to my question, but would like to get confirmation of my conclusion from the experts. My dilemma concerns the "accuracy" of taxonomic species classifications as to conspecificity of different forms. As you likely know, across the geographic range of similar life forms, not all scientists are in agreement over which ones belong to the same species or not, and may "split" or "lump" them into the same or different species based on different criteria. For example, the African elephant has traditionally been treated as one s…

Hello, i am looking for a plant-biology expert, what would you say ? Which one is more complex? C3 or C4 photosynthesis ? I had a debate with a guy who has an education in plant biology, and i was told that C4 photosynthesis is a sort of C3-downgrade ... i was told, that the C4 excluded a very complex photo-respiration step, therefore, the C4 is less complex, it is a 'C3 downgrade' and easy to evolve 60+ times over and over (by convergent evolution) However, from what i could understand, the C4 is more complex, because there are newly evolved steps, newly evolved specialized cell anatomy, which seems to be more complex... So which one is more com…

55 million years ago, the world was literally a jungle. With such high temperatures, rainfall and humidity, life could proliferate. But 49 million years ago, something drastic happened: The Azolla Event, where ice was forming at the poles. The culprit? A kind of plant called Azolla. Within 800,000 years, photosynthesis and carbon sequestration from those plants reduced the atmospheric quantity of carbon dioxide from more than 3000 parts per million to 650. [figure from Atmospheric carbon dioxide concentrations over the past 60 million years] But the real question here is--did the cooling caused by the Azolla Event create a major extinction event …

Hi, I have a question about the evolution of sexual traits I want to understand. Specifically, the lion's mane, another animal that's a perfect example is the male peacock. The way I percieved what I've read about this morphed trait (mane of lion) is that a male has a mane because the females favored it the same goes for the beautiful feathers of a male peacock. So how does a trait such as a mane know the opposite sex favors it? For one thing didn't it have to be there first for the opposite sex to know if they liked it or not?

Since we have no free will, what purpose does/did consciousness serve? For the purpose of this topic, let us assume that free will does not exist. I do not believe in it, and I am not trying to debate its existence. And I am not the sharpest knife so don't hesitate to correct me if I am wrong about something. This is being asked purely from curiousity. I have been very troubled recently, and I have been turning this idea around in my head over and over again. Doesn't the absence of free will (that is to say that all lifeforms are nothing more than calculating machines) make consciousness pointless? We are robots whose only purpose is to not die and have sex. …

These are questions where I have struggled to find answers. How did instinct arise? How did it become "embedded" in species of animals? Are the changes epigenetic and passed on in subtle base modifications (e.g. methylation)? Do instincts change? The Great monarch butterfly seems to use the sun to guide itself huge distances. I wonder if the amount of sunlight is a cue that then allows instinct to fly to "kick in"? Great monarch butterfly

Has any experiment been done to create new un-interbreedable species by artificial selection? I am assuming this experiment would have to go on long enough for the new species to be placed in a different category from the original species. The higher up the category the better (ie: order>family>genus).