Principles Of Evolution Flashcards
What is evolution?
The change in inheritable characteristics of populations.
What was Cuvier’s idea?
Catastrophism which is species could not change but instead could become extinct from things like earthquakes, floods, etc.
What was Hutton’s idea?
Gradualism which is changes observed resulted from slow changes over periods of time.
What are aqquired characteristics
a modification or change in an organ or tissue during the lifetime of an organism due to use, disuse, or environmental effects, and not inherited.
What is change over time
the process of heritable traits in populations changing over successive generations, leading to adaptations and potentially new species.
What is fossil aging?
Determining the age of fossils
What is the law of superposition
In a sequence of sedimentary rock layers, each layer of rock is older than the layer above it and younger then the rock below it.
Define species
A group of organisms that can reproduce and have fertile offspring.
What is Darwins theory of evolution by natural selection
natural selection is the mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
What is variation
a difference in a physical trait
How can variation benefit a population
Natural selection can act only on traits that already exist so the different traits will become beneficial.
What did Darwin observe while at the islands
Fossil and geologic evidence supporting an ancient Earth. Differences among island species.
What age did Darwin claim earth was
Didn’t claim a specific age but around 4-6,000
What is artificial selection
The process by which humans select traits through breeding.
What are examples of artificial selection?
Good doodle, man made from forcing poodle and golden retriever to mate.
What is natural selection
A mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
What are examples of natural selection
Long necks of giraffes to get food.
What does natural selection act upon
Traits that already exist.
What did darwins theory not explain?
The mechanisms of inheritance and the origin of variations.
What is adaptation
A feature that allows an organism to better survive in its environment
How does adaptation benefit an organism
They can lead to genetic change that Lets them better survive in an environment.
What are the four main principles of the theory of natural selection
Variation, Overproduction, adaptation, descent with modification
What pieces of evidence are used to support Darwins theory
Fossils, geography,Embryology, anatomy, molecular and genetic evidence.
How is the fossil record used as evidence of evolution
by showing the progression of life forms over geological time, demonstrating the existence of extinct species, and revealing transitional forms that link past and present organisms.
How is mutation important to the theory of evolution
they introduce genetic variation, the raw material upon which natural selection acts, allowing populations to adapt and change over time.
What do similarities in embryos suggest about organisms of different species
A shared evolutionary history and common ancestry.
what is biogeography
The study of the distribution of organisms around the world
How is biogeography used to support evolution
by demonstrating how the geographical distribution of species reveals patterns of evolutionary relationships and adaptation to specific environments, including the impact of continental drift and isolation.
What are Analogous structures
Similar in function but different in structure.
What are homologous structures
Similar in structure but different in function.
what is vestigial structure
remnants of organs or structures that had a function in an early ancestor.
What are pseudogens
sequences with no ,onger funtion, carried along with functional DNA, can be clues to common ancestor.
What are the various ways in which fossils are formed
Permineralization, natural cast, trace fossils, amber preserved fossils, preserved remains.
What is a transition fossil
form when an entire organism becomes encased in material such as ice.
What is relative dating
Compares the placement of fossils in layers of rock to estimate the time during which an organism lived.
What is absolute/radiometric dating
Decay of unstable isotopes which provides an accurate way to estimate the age of fossils
What is half-life?
the amount of time it takes for half of the isotope to decay.
What is an index fossil?
existed only during specific spans of time and occured in large geographic areas.
What is the geologic time scale?
A scale that divides Earth’s history based on major past events.
What are isotopes?
Atoms of an element that differ in their number of neutrons.
