Tommy asked in Science & MathematicsBiology · 2 months ago

Can u explain difference between genetics and natural selection?

1 What is the cause of down syndrome genetics or natural selection?

2. What is the reason when a person stops growing? natural selection or no?

1 Answer

  • Anonymous
    2 months ago

    Natural selection is the  ability of some organisms to survive and reproduce better than others because the genes they have give them the advantage.

    Genetics is the scientific study of how genes work and how they increase or decrease in frequency, how they are passed along to future generations and how they give organisms the advantages in survival or reproduction. Hw genes are expressed or how they are controlled are also topics of interest.

    Genes are packed into chromosomes. Down syndrome is caused when an extra chromosome is present in the fertilized egg because either the sperm of the father or the egg of the mother contains an extra chromosome. It is a mistake that occasionally happens when sperms or eggs are produced. People with Down syndrome will be sterile as adults. As a result, Down Syndrome patients cannot pass along their illness to future generations. Down Syndrome is genetic defect that is eliminated by natural selection. The production of sperms and eggs are also processes that can be subject to natural selection. Organisms that produce lots of defective sperms or eggs will be eliminated by natural selection as well. 

    We stop growing because our genes inform our bodies how long we should continue growing. Those genes are in term subject to natural selection and they are the result of many generations of natural selection.  Some genes have been subject to natural selection for as long as billions of years.  Some genes are more recently evolved but they are also subject to natural selection.  Some organisms, such as pumpkins, can grow to enormous size because their genes do not tell them to stop growing. OTOH, many species will not grow past a certain size range, and that includes us. We will not find humans that are a hundred times or even twice the  height of the average person because of genes. However, the reason we do not grow to the size of elephants is because of natural selection over hundreds of thousands of years of natural selection. Climate determines how tall we can grow because tall people will lose heat more quickly. Therefore people who live in forest environments and in cold climates tend to be shorter. The ability to hunt also determines on how tall we could get (at least before the invention of agriculture) because hunters that are too tall may not be able to conceal themselves during a hunt. If a person has genes that let him/her grow to enormous size, he/she may not be able to survive long enough to reproduce to pass on those genes. Genes therefore determine what how our body is and how it works, and those genes are subject to natural selection. Natural selection can increase the frequency of some genes or wipe them out altogether.

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