10.4 Evidence for evolution Flashcards
What is the theory of evolution?
It describes the way that organisms evolve and change over many years as a result of natural selection
That organisms that are adapted to their environment have better chance of survival and reproduce passing on the characteristics to the offspring. Then gradually specie will change overtime to have more advantages phenotype for the environment it lives in.
How do scientist do to study the process of evolution?
Paleontology - studying fossils and fossil records
Comparative anatomy - The study of similarities and differences between organisms anatomy
Comparative biochemistry - The similarities and differences between the chemical make up of organisms
How are fossils formed?
When animal and plant remains are preserved in rocks
Then overtime sediment is deposited on the earth to form layers of rock… different layers corresponding to a different era
Within these different rock strata fossils are found
What evidence does Fossils provide? What does it show?
Supports the evolutionary theory that simple life forms gradually evolved over extremely long time period into more complex ones - as simple life forms found in the oldest rocks and vertebrates in the newer rocks
The sequence in which they are found in matches their ecological links to each other - plant fossils found before animal fossils
Proves the relationship between extinct species and living spices - allows us to investigate
Allows us to study the similarities and differences in the anatomy of fossil organisms - which allows to know how closely related organisms have evolved from the same ancestor
Why are fossils complicated to use to prove evolution? Why are there gaps in the records?
Fossil records are not complete - as many species are soft bodied and decompose quickly before they have a chance to fossil-ate
Conditions that are need for fossils to foscilate is not always available
Many other fossils have been destroyed by Earths movement
Some are uncovered
What is comparative anatomy?
The study of similarities and differences in the anatomy of different living species
What is homologous structure?
Is a structure that appears superficially different (and may perform different functions) in different organisms.
but same underlying structure
What is comparative biochemistry?
Is the study of similarities and differences in the proteins and other molecules that control life
How is comparative Biochemistry be done?
Scientist get two species and compare the molecular sequence of a particular molecule ( Scientist do this by looking at the order of DNA bases, or at the order of the amino acids in a protein)
Then scientist plot a graph with the number of differences that exist against the rate the molecule undergoes neutral base pair substitutions (which gets determined during studies)
From this, the scientist can estimate the point at which two species last shared common ancestors. Species that are closely related have more similar DNA and proteins.
How can Comparitive Biochemistry and Palaeontology be used to support the theory of evolution?
It allows Scientists to determine the relationships between ancient species
How did the theory of evolution develop overtime?
Begin of time, people believed in the Christian Bible that God had created everything including human beings. That life was created only a thousand years before.
[Principle of Geology]
Darwin read this book which was written by Lyell. He suggested that fossils were actually evidence of animals that have lived million of years ago
It also brought up the idea known as Uniformitarianism…. the idea that the Earth was shaped by forces: wind erosion, river sedimentation etc. Saying it is a natural process.
=> This lead to Darwin thinking that evolution is a slow processes
[Darwin’s observation]
Darwin did observations in finches in the Islands. During that time he sent species back to the UK for them to preserve and classify. Allowing them to spot links with other species that Darwin did not pick up and to observe their characteristics first hand. Were he came up with these theory:
Species that are well adapted to the environment will survive longer than species that are less suited. Therefore, it will have more offspring and pass on its’ characteristics. As a result, overtime the whole population will share the same characteristics
Darwin also carried out experiments of breading pigeons to gain direct evidence of his work.
[Alfred Wallace]
Was working on his theory of evolution at the same time and peered review his work with Darwin. He had the same theories as Darwin
They both go on together to release the information to the public. Were Darwin published Origin of species and Wallace independently came up with the theory of evolution by natural selection.
Why was Darwin’s work considered as controversial topic?
Because his theory conflicted with religious views that God had created all of animals and plants on Earth
Darwin’s idea of Human evolving from apes, conflicted with the idea that God created Man from his own image
What is embryology?
is the study of embryos
What is an embryo?
Is an unborn (unhatched) animal in its’ earliest phase of development
Why do embryos prove the idea of evolution?
Embryos develop in a similar way and can be difficult to tell apart - which imply that the process of embryonic development have a common origin. As they share same traits.
