Evolution refers to the observed changes in successive generations of biological organisms due to heritable components (genes and DNA). Charles Darwin proposed a major mechanism of evolution: natural selection.
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Evolutionary explanation to why we have such large memory capacities?
The scientific consensus is that no one ever fills up their memory capacity by learning facts and so on, even in the information age. My question is therefore, is there an evolutionary reason as to ...
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Why are eggs “egg” shaped?
Is there a reason as to why chickens lay "egg" shaped eggs, as opposed to spherically shaped eggs (or a random shape)? <--- Main Question
For extra points (actually just to add more words in ...
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Evolution in 37 years, is it possible?
I am confused, can evolution ( speciation ) really occur in such a short time ?
In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the ...
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How did the huge dinosaurs cope with gravity and loads on bones, etc.?
It's very costly to be a huge animal. Your mass grows in cube when you scale up, but you still only have two/four legs to support the same weight. This increases the pressure that your body needs to ...
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Historical recovery from mass extinction events
Is there a way to generally characterize how species "regrew" after the various mass extinction events happening periodically from 450 Ma to 65 Ma. Would the surviving species just start back where ...
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Would ovoviparous to viviparous mutation have been gradual? How would that work?
It seems unlikely that an ovoviparous ancestor of mammals long ago could have had a viviparous offspring in a sharp one-generation dividing line, but what would be the gradual steps between egg birth ...
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Chromosome 2 fusion?
I read this article by Jeffrey Tomkins and Jerry Bergman claiming to debunk chromosome 2 fusion. Is there anything wrong with these conclusions?
" 1.The reputed fusion site is located in a ...
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What is the evolutionary rationale for palm sweating?
Sweaty palms seems to be a reaction to stress, anxiety, etc. For our forest-inhabiting primate ancestors sweaty palms could cause unwanted side-effects such as slipping off tree branches under ...
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Why is Galapagos island so special?
I am not a biologist so the question may be very stupid. I have no idea. Why did Darwin formulate his theory of evolution just after his visit to the Galapagos island? Why is it so special from the ...
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Which came first: The Chicken or the Egg? [closed]
Has there been any serious scientific inquiries into answering this age old question?
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How can I compare rates of evolution for two sets of proteins?
I have a list of candidate proteins as the result of my analysis. I am now trying to find various characteristics that they have in common. One of the things I would like to check is if my candidates ...
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Resources for learning Anthropology [closed]
I'm a programmer by profession and passion. I've been interested in biology, especially regarding evolution in school. Now I would like to learn Anthropology in my free time. Can you point me to some ...
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Colonial Cells Demonstrating Cell Specialization
Are there any living examples of cellular colonies demonstrating very primitive cellular specialization? If so, what do we know about how they assimilate? How independent are the individual cells ...
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What is the modern state of the theory of evolution?
When I studied biology at my medical school we used to learn things about a century old: the famous Darwin's voyage on "Beagle" to the Galapagos Islands, the classical triad of his Theory of ...
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What measures are commonly used for the complexity of an organism?
I'm aware of measures like number of distinct cell types being used as a measurement of complexity in biology, for example in the G-value paradox. But this doesn't really help for unicellular ...
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Is there any complex organism that is both autotroph and heterotroph?
Possibility also include "adaptation mode" if such exist. I don't discern whether autotrophic/heterotrophic part play only minor role either.
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Good book on Origin of Life [closed]
What is a book that goes into reasonable detail (but isn't textbook-level technical) about the origin of earth and in particular the origin of life on earth? Something intended for a broad audience, ...
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How to get smallest subtree containing a set of nodes from BioPhylo?
I'm testing out various phylogenetic libraries in Python. I want to read in a Newick tree, then, given a list of taxa, generate the smallest tree that contains them all. This task is quite simple and ...
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Nucleotide frequencies in Kimura's two-parameter model
Here's an excerpt about Kimura's two-parameter model from Felsenstein's Inferring Phylogenies:
"The model is symmetrical, and one can immediately see that, after
enough time has elapsed, it ...
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Are genes associated with obesity selected for?
I've read that there are several SNPs associated with increased risk of clinical or morbid obesity. I was wondering if there is any evidence that these are under positive selection. Would you expect ...
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Is there a timeline for the frequency of evolution of any species?
Evolution is traditionally spoken of as an inherited change over generations.
Does evolution happen one change at a time - or are there multiple changes occurring between two successive generations? ...
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What are evolutionary implications of contraception and reduced childhood mortality rates worldwide?
I've heard the following idea this morning: Before the introduction of contraception, humans conceived quite a lot of babies (there was little to do to avoid that), but the population was kept in ...
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Height and natural selection in humans?
I watched the documentary "Evolve" recently and in the segment on "size" Scott V. Edwards, Harvard evolutionary biologist mentioned the idea that humans might evolve to be 7' tall in 'hundreds of ...
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What preceded ATP synthase?
ATP Synthase is ubiquitous throughout life on earth and so most probably evolved within the last universal common ancestor (LUCA) before that lineage diversified into the various kingdoms of life.
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I believe in variation of a species but not in evolution [closed]
I can see that variation within species exists, for example birds with various size beaks adatpted for specific food gathering puposes, one may have a larger beak vs smaller beak, ok that works for ...
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How did giraffes develop their rete mirabile failsafe?
Giraffes, being one of the tallest mammals in the world, have a failsafe called rete mirabile to prevent them from dying from excessive blood pressure while lowering their head.[1]
Due to their long ...
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Birds from the Family Columbidae Feed Young “Crop Milk”
Birds from the family Columbidae (e.g., doves and pigeons) produce a fatty, milk-like substance in their crop. The secretion is often referred to as "crop milk." They feed crop milk to their young ...
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Fossils of intermediate stages?
If Humans are evolve from Monkeys, there must be stages in the evolution process, when it was 1% human and 99% monkey, 2% human and 98% monkey and so on. This is because evolution was a very slow ...
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What selective factors drove the evolution of lactose in lactation?
As far as I can determine, lactose, and the monosaccharide galactose have few biological uses outside of mammalian lactation. It not only required enzymes for its production, but enzymes in offspring ...
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Is better healthcare a bane to the long-term survival of the human race?
The theory of natural selection has it that individuals with better genes tend to survive and reproduce, passing their genes to their offspring. This gradual process results in a population more ...
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Is there a comprehensive database of fossils (with images) online?
Not sure if this is the best stackexchange to ask...
I have not been able to find a decent database of fossils on the web, does one exist?
Here are some of the links I have found through Wikipedia ...
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Why does so much variation exist within species?
My last phrasing of this question did not go down well, so I will try again.
The genotype of species is not always the same. If you ask yourself why not all of these possible expressions except one ...
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Predators faking to be not hungry?
I believe that there are predator/prey combinations where the prey can easily spot that the predator is not hungry and will not try to flee from it. I’m thinking, for example, of gazelles who will ...
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Is there any evidence that a virus can modify human evolution
I was just reading Evolution of lactose tolerance, and in it one line says "But there was a time in human history when our diet and environment conspired to create conditions that mimicked those of a ...
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What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?
I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years.
Can someone explain in ...
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Why Didn't Evolution Cause the Human Body to become Streamlined?
If streamlining makes movement/locomotion quicker and easier, why didn't the apes evolve into life-forms that had streamlined bodies (much like fish)?
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Are there genes in humans from the common ancestor of all organisms?
How long ago can human genes be traced? Are there any genes that go back unchanged to the beginning of life on Earth? And if so, how many?
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Were there lifeforms before LUCA?
This question got me thinking about something. LUCA is the last universal common ancestor of all current living organisms, which is a very different definition from the first-ever living organism. Is ...
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Has the human 7-day week had any impact on the evolution of species?
Most (if not all) industrialized countries follow a 7-day work week now, such that we are bound to follow a certain weekly trend in matters such as pollution generation, where to go (e.g. stay in town ...
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Why can't humans drink sea water?
Why can't humans drink sea water?
It would seem to be a huge evolutionary advantage for an animal to be able to drink sea water rather than have to rely on fresh water, and it's provably not ...
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Disadvantages of unihemispheric sleep
Is is well known fact that marine mammals and some birds can sleep with one brain hemisphere at a time, since it's essential for their survival.
However, at least in my opinion, such mechanism would ...
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Why do plants have green leaves and not red?
I know plants are green due to chlorophyll.
Surely it would be more beneficial for plants to be red than green as by being green they reflect green light and do not absorb it even though green light ...
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How did the first self replicating organism come into existence?
When people try to explain evolution, they tell me that evolution is a cumulative result of mutations & natural section of the more superior individuals of a particular species. I think I'm fairly ...
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Biology view on trait variability
In reading the annotated Origin... I have come to the following note by Costa on p. 168:
Again, modern biologists would disagree with Darwin's idea that especially well-developed traits vary to a ...
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Preserved alpha complementation over evolutionary time?
Has the result of alpha-complementation ever happened via mutation through evolutionary time, and been preserved in modern day organisms?
In other words, has a functional gene product ever been split ...
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Can epigenetic changes affect reproductive success?
This is prompted by niallhaslam's answer to this question [Since Darwinian times, has there been any striking/notable effects of evolution on humans?]. A comment by Alan Boyd asks whether epigenetic ...
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Is there an evolutionary reason for the 5 electron transport complexes in plants and animals?
The electron transport chains of both the light reactions of photosynthesis (in plants) and oxidative phosphorylation (in animals) both contain 5 complexes including ATP synthase, as shown below.
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Since Darwinian times, has there been any striking/notable effects of evolution on humans?
I understand that evolution is constant process that acts on a population in successive generations. Thus, it is obvious that evolution is happening. However, I'm curious as to the stricking examples ...
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Is it possible to increase lifespan through controlled evolution?
A few years back when I was reading The Selfish Gene by Richard Dawkins, there's this short passage where he theorizes about a way to achieve an increased lifespan through controlled evolution.
The ...
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Why was polyploidy not lethal in certain octodontid rodents?
As discussed in Why is polyploidy lethal for some organisms while for others is not?, polyploidy is normally lethal in mammals.
However, two species of Octodontidae (South American rodents), are ...
