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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The evolution of dogs through domestication and artificial selection
I am currently reading Richard Dawkins's book 'The Greatest Show On Earth: The proof for evolution' and in the second chapter he talks very much about the evolution of dogs.
He says centuries ago ...
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654 views
Why do we grow so much hair on our heads compared to our bodies?
I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
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Did animals evolve from plants?
Did animals evolve from plants? Did the animals' ancentors have chloroplasts in their cells?
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137 views
Did we first have swimming birds or flying birds?
Looking at the swimming birds building nests just across my garden, I suddenly wondered how evolution came to swimming birds and whether flying birds started swimming or whether swimming bird like ...
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Are there any structures in mammals that are used only by males?
There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
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102 views
Why is selfishness the 'obvious' strategy?
Thinking of behaviours an organism can adapt, at the very base an action can always be either selfish or altruistic (cooperative).
Usually, selfish behaviour is assumed to be the preferred choice and ...
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How did the human brain evolve?
A common question posed is, "how did the eye evolve?", because the eye is so complex. However, this has been answered rather clearly and there are several examples around the world of animals in ...
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335 views
Is there an evolutionary advantage to crying when sad?
It seems as though the act of crying when sad does nothing to relieve that sadness. Is there an advantage to crying from an evolutionary perspective, or is it the end result of a different process? ...
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515 views
Why do men have nipples?
I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
...
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In which order did the cells of the immune system evolve?
Thinking about how complex the interactions between different types of immune system cells (T-helpers, T-Killers, Phagocytes, B-Cells etc.) are, it's fascinating how they all combine to get the ...
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Why is 'Grudger' an evolutionary stable strategy?
I am currently reading 'The Selfish Gene' by Richard Dawkins, which I am sure many here have read. The topic are evolutionary stable strategies (ESS) regarding cooperation.
I apologise for the long ...
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What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?
I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage?
For example, consider a ...
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Is there a dominant gene for right-handedness?
Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular ...
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How did viruses come to be?
My question is out of curiosity and got me thinking. How did viruses with the head, tail and tail fibres actually evolve? These viruses look more like machines than biological entities. Are there any ...
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How do we know that dinosaurs were related to lizards and/or birds?
Do we clearly know what the living closest relative of the dinosaurs are? And connected to the first question, in scientific manner how do we know these relationship between extinct species and living ...
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How To Avoid Macro-Evolution Confusion? [closed]
I regularly encounter students who believe humans came from amoebas and when asked why they often say Macro-Evolution has been scientifically proven.
Macro-evolution is defined as evolution at or ...
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158 views
What was the reason for some plant and animals to become giant in course of evolution?
The dinosaurs, mammoths, giant plants etc are known to be bigger than modern animals. I wonder why they had been lived and why they are not living now? I really don't know much but is it something ...
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Can species back-evolve?
One of the tenets of Darwin's theory is the survival of the fittest, ie adaptation of features that allow a species to adapt better to its surrounding environment. I am wondering that given the right ...
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How does population stability evolve?
The number of individuals constituting a population is called population size. Over time population size does not remain constant, it fluctuates to different extent over generations because of ...
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Why do eukaryotic organisms have introns in their DNA?
We touched on introns and exons in my bio class, but unfortunately we didn't really talk about why Eukaryotes have introns. It would seem they would have to have some purpose since prokaryotes do not ...
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What evolutionary mechanism caused felines to develop purring?
And why can some felines roar while others meow?
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Are there differences in DNA between humans of today and humans from 2000 years ago?
Are there any significant differences in our genome compared to the genes of our ancestors from 1000-2000 years ago?
And if there are significant differences, do they result in significant ...
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Do men have more extreme variations than women?
This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences
I was reading this article which I found interesting. It is not supported with ...
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399 views
What is the evolutionary advantage of death?
I know death and cancer doesn't hurt humans' reproductive success. It's not helping either.
Why do we die? Why dying humans (all of us) are common? What's the point of dying?
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What do we know about LUCA?
All life on Earth (bacteria, archaea, eukarya) is thought to have evolved from a common ancestor, or last universal common ancestor (LUCA). What do we know about the characteristics of LUCA based upon ...
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What are the evolutionary niches differentiating an apple from a pear?
So, as far as I understand (basic) evolutionary theories, diversity is generated by "niching." That is, if there is an environmental factor that hasn't been fully used by any species to "profit" off, ...
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236 views
How does “be altruist to those who are similar to you” evolve?
There are many cases when people commit altruism. One is relationship. I am willing to die for 2 of my children or 8 nieces, say an evolutionary psychologist. Another is reciprocal altruism, which is ...
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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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Why do pandas have a high probability of giving birth to twins?
According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
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What is the closest species to humans in animal kingdom?
I presumed chimpanzees were the closest relatives of us. However, after watching this TED Talk, it seems bonobos are closer to us both in skeleton and behavioral similarity than chimpanzees. I once ...
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Evolutionary origin and exogenous cues of ~28 day infradian rhythm?
The most obvious example of an approximately monthly biological cycle is the human menstrual cycle. My questions are the following:
Is it known when and where this cycle or one like it arose?
What ...
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Can two humans with 44 chromosomes produce viable offspring?
It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes.
One example is a male in China: the first article, the second article.
The other is a female in ...
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Is there any reason for the variation in mitochondrial DNA size?
As my textbook An Introduction to Genetic Analysis points out, yeast mitochondrial DNA has approximately 78 kb of genetic data, while the human mitochondrial DNA contains 17 kb. Is there any evolution ...
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253 views
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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Is there are evolutionary explanation for why humans and primates are ticklish? How might it have evolved?
Tickling is a rather interesting phenomenon: When humans or apes are touched in certain areas like the armpits or sides, we respond with laughter AND frantic attempts to stop the assault. Obviously ...
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How many times did life emerge from the ocean?
Evolution is often mistakenly depicted as linear in popular culture. One main feature of this depiction in popular culture, but even in science popularisation, is that some ocean-dwelling animal sheds ...
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Why is polyploidy lethal for some organisms while for others is not?
Polyploidy is the multiplication of number of chromosomal sets from 2n to 3n (triploidy), 4n (tetraploidy) and so on. It is quite common in plants, for example many crops like wheat or Brassica forms. ...
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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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Why do some plant species have lobed leaves, while similar species in the same habitat don't?
Some plants have lobed leaves, like the English oak (Quercus robur), while other plants growing the same deciduous woodland habitats, and very often growing alongside oaks, such as the European beech ...
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Is Behe's experiment (evolving the bacterial flagellum) plausible in the lab?
[Warning: this question is motivated by a prominent proponent of "intelligent design": Prof. Michael Behe. I'm not interested in debating creationism.]
According to Wikipedia[1]:
In Darwin’s ...
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Is it the case that all changes in phenotype during life are not inheritable?
This came up in a talk with a friend. I wanted to clear this doubt. I've read about it before and did again after her remark (my thoughts didn't change: her concept is Lamarck's, not Darwin's), but ...
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What is meant in biology by the term “evolved”?
A student asked me this the other day and I thought that I would ask it again here. If one organism is said to be "more evolved" than another, what exactly does this mean?
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Did human hairs actually evolve from scales?
What is the evolution of hairs? Did they evolve from scales?
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135 views
What is the benefit for cells having the ATP production regulated in mitochondria compared to being from the nucleus?
Mitochondria have their own DNA and appear to be loosely connected to the nucleus and it role.
Why are the functions of mitochondria not in the nucleus? Why doesn't the nucleus control the ...
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When did vision evolve for the first time?
Today I wondered what the first organism to evolve vision would have been. I assume that it would have been kind of primitive and basic, but of course extremely innovative and eventually useful to a ...
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Why have humans evolved much more quickly than other animals?
Humans have, in a relatively short amount of time, evolved from apes on the African plains to upright brainiacs with nukes, computers, and space travel.
Meanwhile, a lion is still a lion and a ...
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Are there any examples of sudden leaps in evolution?
As far as I understand, various abilities like flying, sight, hearing etc. were caused by slow evolution, where those with a greater ability to to these things had better chance of survival. (If this ...
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How do members of cryptic species know who to mate with?
According to Wikipedia:
In biology, a cryptic species complex is a group of species which
satisfy the biological definition of species—that is, they are
reproductively isolated from each ...
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Did researchers evolve multicellular yeast or did they just turn on multicellularity?
In this new paper "Experimental evolution of multicellularity" found via Ars Technica the researchers describe having developed multicellularity and apoptosis within 60 days from a unicellular yeast ...
