Get Started. It's Free
or sign up with your email address
Evolution by Mind Map: Evolution

1. The change in traits over time

2. Biochemicals

2.1. DNA

2.1.1. basic genetic material, made up of a combination of a 4 letter code that corisponds to a specific nigrogen base, sugars, and phophate groups

2.2. Genes

2.2.1. Made up of DNA, controls the traits of an individual, some have instructions on how to produce proteins

2.3. Protiens

2.3.1. Made up of amino acids, they build and operate organisms at a cellular, tissue, and organismal level.

3. Gene Variation

3.1. Gene variation is caused by mutations in the DNA. Everytime DNA replicates, it has a chance to mutate. these mutations happen in three ways, substitution, where a gene is substituted for another, insertion, where another gene is added to a spot already containing a gene, and deletion, where a gene is completely removed from the chain

3.1.1. these mutations can be either beneficial, harmful, or affect absolutely nothing.

3.1.2. mutations are how traits are changed, which is the driving force of evolution

3.1.3. these mutations could be passed down to the organism's offspring, leading to them mating and spreading the mutation alog through the generations

4. Evidence for Evolution

4.1. It is belived that all species on earth have evolved from common ancestor that lived thousands of years ago

4.1.1. One way that we can prove that there was life before our current species, and thus we can have common ancestors, is the fossil record. When looking at fossils, the fossils that are closer to ground level are from species that are more closely related to species that lived today, because their fossils were formed later than a fossil that is buried deeper

4.1.2. Another way we can prove that we descended from common ancestors is through comparative biology. This is when we compare the traits and characteristic of species to determine if they are somehow related

4.1.2.1. DNA technology has been an enormous breakthrough for determining whether or not different species are linked to a common ancestor, as it uses quantitative evidence instead of qualitative. This is because DNA programs proteins, and proteins are responsible for the different traits we have, so by looking at the DNA sequence of different species we can determine how closely related they are by determining how many different genes they share.

4.1.2.2. We can also compare the different embryos of species who have common ancestors. This process is called comparative embryology. one example of this is by looking at the embryos of a rabbit and a fish. to the untrained eye, they look nearly identical. by analysing the similarities and differences, we can link different species to a common ancestry

5. How does evolution happen?

5.1. Artifical selection

5.1.1. Artifical selection is when human specificly breed orginisms that posess a specific trait so that their off spring will possess that trait. One example of this breeding dogs, as someone could take a dog who has a certain fur type, and specificly breed that dog so its offspring will also have they type of fur

5.2. Natrual selection

5.2.1. In nature, evolution can be a bit complicated. For the most part, breeding in the wild is random, thus having specific traits that allow for an organism to reproduce more are desirable. This is how many helpful traits become common in a species, and with enough of these specific trait changes, new species are created

5.3. Sexual selection

5.3.1. In nature, many species choose their mate. This leads to what we call sexual selection. in this process, the female may decide to only breed with male birds who have specific traits, like in birds where some males may have ornamental feathers, or other structure to attract a mate. because these males need to have these specific traits to attract a mate, it leads to what we call dysmorphia, or when the diffrent sexs of a spieces look vastly different

5.4. Genetic drift

5.4.1. This is the most rare way that evolution happens. Genetic drift is when the allele frequency of a sepeice changes due to chance. While most species have a large enough population to ensure this does not happen, there are specific times when genetic drift is more likely to occur.

5.4.1.1. Another instance where genetic drift can occur is when a group within a species is separated from the main group of a species. This can happen when new colonies are formed, or when a natural barrier splits the two groups. again, due to the lack of competition, a change in an allele for one family may affect a much larger group

5.4.1.2. The first is after a major loss of life, like after a natural disaster, a disease, or after humans have reduced the population. This means that there are less of that animal left, causing what would normally just be an allele change for a family, to affect the entire species, as the carrier of this new trait is more likely to breed due to lack of competition.

6. Speciation

6.1. When a group of organisms have specific traits that set them apart from their orignal speices and they can no longer interbreed with their orignal species, they become a new species.

6.1.1. Sympatric Speciation

6.1.1.1. the group lives in the same area as the main group but does not reproduce with the main group

6.1.1.1.1. Prezygotic

6.1.1.1.2. Postzygotic

6.1.2. Allopatric Speciation

6.1.2.1. The group develops diffrent traits due to being georaphicly sperated from the main group