Changes in the heritable attributes of populations of organisms over time. Major mechanisms include drift, natural selection, mutation, and gene flow (migration).

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Why does human facial and head hair continue to grow?

Many people can grow extremely long head hair and facial hair. Are there evolutionary theories as to why this is the case? It seems like having long hair could be a disadvantage, and extremely long ...
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2answers
125 views

Won't natural selection miss the overall minimum of a function?

Suppose we have a population of about 1000 with an environment that does not change a lot (e.g. the atmosphere is more or less the same) and we leave this population to evolve. From what I understand ...
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95 views

How to define “evolution”?

The standard answer to: what is evolution? is: It is a change in allele frequency over time! I believe a complete definition should encompass the following concepts: mutations copy ...
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1answer
114 views

Why insects are so small compared to mammals?

I was wondering what biological limitations make the dimension of the insects small compared to the dimension of the mammals. I know in other eras insect were bigger!
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133 views

Which statement about phenotypic plasticity is false?

This was a test question, and I'm not too sure about the answer. Which statement about phenotypic plasticity is false? a. Because the plasticity of a phenotypic trait may be costly to maintain, it ...
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334 views

What does fitness really mean?

Fitness is certainly the most important concept in the theory of evolution. My question does not have to do with practical measures of fitness but with the theoretical definition of it. I am a bit ...
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241 views

Genetic variation and sensitivity of wild cabbage

1: Is it true that the genetic variation of kale plants is smaller than wild cabbage? I think so, because of human selection of the kale plants. 2: Are broccoli and cauliflower more ...
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1answer
79 views

Which mountain range was formed first (historically) and which the pedigree is correct?

Source 1: Source 1 shows a map of a particular area. In this map you will find the mountain ranges 1 and 2, the species P, Q and R. Two possible pedigrees of the ancestral history of the species ...
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107 views

Examples of virus originated from a living system

Do you know some examples of virus or a viroid (or a prion) that originated from a known living organism? How does the virus/viroid/prion lives? Does it paratize the organism from which the virus ...
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23 views

What is the origin of viruses? How could they get both living and non-living characteristics? [duplicate]

I read that viruses are called intermediate between living and non-living particles. Well, if so, then where did they originate from? From living or non-living? If they originated from either living ...
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2answers
177 views

Eusociality and Natural selection?

Eusociality, particularly focusing on the presence of certain altruistic sterile organisms within the social set-up creates questions as to why would the process of natural selection have favoured the ...
8
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1answer
548 views

Could humans and chimpanzees hybridize?

In some cases two species can hybridize. For example, Tigers and lions can hybridize to produce "Ligers". Would it also be possible for humans and chimpanzees (or any other species) to hybridize ? ...
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67 views

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 ...
2
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1answer
118 views

The concepts of relatedness - Hamilton's rule and kin selection

Here is a quotation from this wikipedia page The relatedness parameter (r) in Hamilton's rule was introduced in 1922 by Sewall Wright as a coefficient of relationship that gives the ...
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1answer
59 views

Who was the first to talk about evolvability?

"Evolvability is the capacity of a system for adaptive evolution." (source) There are several other definitions though: Who was the first person to use the word "evolvability"? Who was the first to ...
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1answer
119 views

Evolutionary Cell Structuring

I'm a total novice when it comes to biology, and I'm really just looking for an answer to a question that has been posed to me by people who deny evolution fervently. Evolution dictates that we've ...
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3answers
630 views

How does the modern theory of evolution solve these apparent problems? [closed]

I hold to the truth of Evolution, but I've encountered several problems with it, that I can't answer, and I can't find an answer for, despite much research. If would be great if anyone can answer ...
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2answers
4k views

Why is glucose our primary source of energy?

Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
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1answer
287 views

Empirical evidence for species selection

Do we have any empirical evidence in favor of species (or lineage) selection? Do we know some cases that can only be explained (or seem to be only explained) by lineage selection? What are today the ...
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153 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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298 views

Why are humans and almost every species on earth symmetrical?

I admit I'm not very learned on the subject of evolution, I just started researching it for myself about a week ago. One of the things that I don't understand is why humans and almost every other ...
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1answer
100 views

What are uses of fossils? [closed]

What are the geological uses of fossils and how could it be utilised? From The Institute for Creation Science: Fossils are typically found in sedimentary rock, almost all of which were originally ...
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1answer
42 views

Variation in MHC in humans

What evolutionary process lead to so much variation in MHC? What is the advantage of having such variation?
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5answers
278 views

Is evolution true as Darwin said? [closed]

I was telling the theory of evolution to my friends. But they asked me for the proof. They said, we are not seeing any such transition species at present. Neither we have such evidence for evolution. ...
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2answers
1k views

Genetically speaking, are dogs exactly similar to humans and chimps both?

Richard Dawkins mentions in his book The Greatest Show on Earth that dogs are exactly similar to both humans and chimps. Supposing that a cell contains the genetic similarity between 2 species, he ...
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1answer
3k views

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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1answer
47 views

Phenoptosis, behavior evolved for good of species?

I was reading this and felt like the argument is being made that organisms die for the good of species. Isn't this nonsense? This especially bugged me: "'Age-induced, soft, or slow phenoptosis'" ...
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2answers
198 views

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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1answer
238 views

Variations in Genome Sizes

Why is there wide variation in genome size amongst groups of protists, insects, amphibians and plants, but less variation within groups of mammals and reptiles?
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1answer
286 views

Are there any 6 limbed reptile fossils?

Were any 6 armed "tetrapod" fossils ever found? I've seen some lobe finned fish with two sets of shoulders in an evolutionary bio book... I'm curious because I'd like 4 limbed and 2 winged dragons to ...
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51 views

Natural selection and the Galapagos Islands [closed]

Woodpeckers found on the South American mainland are able to peck insects from the bark of trees. Would the woodpecker finch have been able to survive if woodpeckers had found their way to the ...
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1answer
103 views

How animals maintain their body shape after development to maturity?

I've recently read a book on evolutionary-developmental biology for laymen, and it described how a fetus is progressively divided into more refined zones of genetic activity. These zones, kinda like ...
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2answers
4k views

Did animals evolve from plants?

Did animals evolve from plants? Did animals' ancestors have chloroplasts in their cells?
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2answers
115 views

How did viruses learn to utilize the workings of a cell?

This is my first post here, so excuse me for its simplicity. Viruses can infiltrate a cell, overtake it and multiply. It has projecting fibers whose ends are shaped as kind of a "key" to a mobile ...
2
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1answer
480 views

Molecular Evolution: Mrbayes never stops?

When I use my own data to build Bayesian phylogenetic trees using the software Mrbayes, after many generations, it never reaches stopping status (namely, the average standard deviation of split ...
8
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1answer
62 views

What does the evidence suggest about how Neanderthals became extinct?

According to "Neanderthals: Facts About Our Extinct Human Relatives" (Szalay, 2013), Neanderthals dominated Europe during the last Ice Age, but may have died out before the arrival of Homo Sapiens ...
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1answer
249 views

evolutionary reason behind sharing the same path for food and air?

What is the evolutionary reason behind sharing the same path for food and air? For example, we have a nose and lungs, yet they are linked by the pharynx, which is shared with the mouth and ...
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2answers
94 views

Why can't cell division happen the other way around?

Mitosis in eukaryotes happen in this order: DNA replicates and then the cell divides. Why doesn't it happen in reverse order (i.e., cell divides and then replicates the DNA)? I am talking about ...
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1answer
548 views

Is there any advantage of having a mitochondria for aerobic respiration?

If we consider the pathway of breakdown of glucose which includes glycolysis, the citric acid cycle and the electron transport chain, all these processes takes place in some prokaryotes and ...
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1answer
221 views

I think evolution has goal [closed]

Richard Dawkins says evolution doesn't have any goal. But I think evolution has one. At the end evolution creates intelligent being. If we find another earth like planet evolution sould have the same ...
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180 views

Are biological systems engineered? They are often reverse engineered at a molecular level!!

Understanding biological systems, molecular biologists need to “reverse engineer” them. Is this evidence that the systems were engineered to begin with?
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1answer
62 views

Is there any definition of complexity about gene and protein according their function?

Sorry for such a question,if it is too naive. Is there any definition of complexity about gene and protein according their function?If so,what is the relation between them?
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1answer
110 views

Was life less colorful before color vision evolved?

According to Wikipedia, we know that color-vision photopigments appeared in the common ancestors of tetrapods and fish at least 360 MY ago. Would life have been less colorful before the evolution of ...
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1answer
39 views

Estimation of number of species at an earlier time

The estimated number of species on Earth, as reported in this article is around 8.7 million. I am fascinated by how nature produces such a wide variety of species. As per my understanding, many ...
5
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1answer
659 views

Smallest unit on which selection can act

Traditionally, the individual was considered to be the smallest unit on which Natural Selection (NS) acts. Today, we usually consider the gene as being the unit of NS. Of course, we should also ...
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3answers
491 views

Is there variation of AT/CG ratio along species?

Chargaff's rules say that the number of Adenine of the number of Thymine in a genome are equal (nA=nT) and similarly nC=nG. This makes obvious sense knowing that C binds to G and A to T. But what ...
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4answers
124 views

How did the activities of protocells become inheritable?

I have learned that first a protocell came to exist and its characteristics came to be passed on by genetic material. So how come genes for all the activities come to incorporate into genetic ...
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1answer
262 views

Does a fully-resolved phylogenetic tree have to be dichotomous?

I read that wherever there is polytomy there is an unresolved pattern of divergence. I don't understand why this is so. When divergence takes place, is it necessary that there will be division into ...
12
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5answers
367 views

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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1answer
101 views

Why can't we propose a solid theory regarding origin of life?

What information is greatly lacking which does not allow us to propose a solid theory for origin of life ?