Evidence in Evolution

Evidence in Evolution

The Fossil Record

The Fossil Record is the record of all known fossils found near other fossils from different time periods (different layers). Changes in species can be seen in each generation. For example you can see the snouts of lizards/ dianosaurs become the beaks of birds.

Similarities in Related Lifeforms

Organisms have three forms of body structures in evolutionary terms. Homologous: Body parts of multiple organisms all come from a common ancestor, but may not all have the same function. Analogous: Body parts of multiple organisms look similar and have similar functions but come from a seperate ancestor. This is proof that all organisms have to adapt to their enviorment no matter their ancestry. Vestigial: Body parts that an organism has but it doesn't have any use for the organism. The organism wouldn't have any reason to have that bodypart if there wasn't a common ancestor with an organisms that does use that part.

Homologous

Vestigial

Similarities in Genes and Chromosomes

When Darwin came up with evolution there was no way to look at the genetics of organisms. Now we can. If you look at an organisms genes and chromosomes you can tell how similar it is to other species. Species that are close in the evolutionary tree of life have similar genetics and chromosomes, proving that they are related.

Embryos and Old Genes

Charles Darwin observed embryos of multiple species. There he saw that species of animals that never had specific body parts had them in embryo form. They woudln't have these parts if they didn't get them from a common ancestor.

Chicken Embryo with teeth that come from it's Lizard ancestors.

Natural Selection

Artificial Selection

Natural Selection is the process by which nature chooses who will survive and thrive and who will die and not reproduce. It's a very simple process that works like this: whoever can get the most food, avoid its predators, and can reproduce the most will thrive. This is one of the biggest components of evolution. This is why in places where the brush is high the herbivores have long necks, all the ones with short necks have long been exinct.

Artificial Selection is the process by which animal breeders produce the best animals for the jobs they need done. They breed two animals that are good at their job to get one that combines their two good traits. For example two race horses being bred to produce an even faster horse.

Analogous

The geographic distribution of related species

Biologests study Biogeography to map out where species and their related species live. When the supercontinent Pangea split so did the species living on each half. This caused the tree of evolution to split. Many of the species in America are closer to eachother than to those in Europe, Asia, and Africa. For example our monkeys are closer related to one another than to Africa's monkeys.