Introduction to Evolution and Evolution Mechanisms

Flashcards covering key vocabulary and concepts related to evolution and evolution mechanisms.

Evolution Hypothesis

Geological evidence and fossil records led some scientists to propose this hypothesis.

Evolution

The change in genetic makeup of populations of organisms over time, leading to greater variety and complexity.

Scientific Evidence for Evolution

Evidence found in fossil records, modification by descent, vestigial structures, embryology, biochemistry and genetics, and biogeographical comparisons.

Natural Selection

A process where organisms with the best adaptations in a population survive and reproduce more successfully, passing on their favorable genes.

Species

A group of natural populations capable of interbreeding to produce viable offspring.

Speciation

The process by which new species arise.

Effective Conditions for Speciation

Conditions such as geographic and reproductive isolation that can effectively lead to speciation, along with natural selection.

Punctuated Evolution

Rapid bursts of evolution interspersed with long periods of stability.

Co-evolution

The evolution of one species in response to another.

Endosymbiosis

One species lives inside another.

Evolution Theory

Theory proposed that Earth is very old and has changed significantly over time.

Palaeontologists

Scientists who study the fossil record.

Geologists

Scientists who study rocks and geographic landforms.

Age of Earth

4.54 billion years old, based on samples from Earth’s crust, moon rocks, and meteorites.

Fossils

Formed when an organism died and was covered by sediment, with minerals filling or replacing the remains.

Fossil Record

Shows an increase in complexity and diversity of organisms over time and a move to a wider range of habitats.

Transitional Fossils

Fossils that reveal stages of transition from one species to another.

Pentadactyl Limb

Having five fingers or toes.

Vestigial Structures

Organs or structures that seem to have no function, indicating a past ancestry where the structure was once useful.

Embryology

Study of how an organism develops from a single-celled zygote; similarities in early development can indicate relatedness.

Biochemistry and Genetics

Similarities in genetics and metabolic processes indicate a common ancestry.

Continental Drift

The continents were once joined together and have been separated by continental drift.

Natural variation in species

An extensive natural genetic variation exists within a population of a particular species and new variations can come about through genetic mutation.

Geographic Isolation

Species are isolated due to continents drifting.

Geographic (allopatric) speciation

When a group of a species becomes geographically isolated from the main body of the population for long enough, it will become adapted to the prevailing conditions in the isolated location, to the extent that the members of that group will become a different species.

Reproductive Isolation

An isolated group of a population may change in some aspect of their reproductive process, to the extent that they will not reproduce with the original population when reintroduced, even if it could be possible.

Punctuated equilibrium

There were relatively long phases in which very little change took place in the variety or genetics of a population, corresponding with stable environmental conditions.

Divergent evolution

Process of evolution and speciation in which the evolving groups have less and less in common with the original one.

Convergent evolution

Evolutionary process in which entirely unrelated phyla have individuals with similar adaptations to perform similar functions.

Coevolution

Populations of organisms that are involved in an interaction, whether harmful or beneficial, evolve through natural selection in response to the relationship.

Symbiosis

A fixed relationship between different species of organisms.

Endosymbiosis

A symbiotic interaction where one of the participants lives within the cells of the other.

Analogous

Adaptations with a similar function and structure, but in entirely unrelated organisms

Anthropocene

The most recent subdivision of the geologic time scale, indicating the period of time during which human beings have existed

Coevolution

A process in which populations of different species evolve as a result of a relationship with each other.

Divergent Evolution

A process of evolution and speciation during which the evolving groups have less and less in common with the original one

Embryology

The study of how a multicellular organism grows and develops from a single-celled zygote (fertilised cell) and early tissue layers

Fossil Record

A scientifically constructed timeline for life on Earth, based on all fossils found, so far, and their ages.

Homologous

Anatomical structures in related organisms, which are similar in appearance, but have different specific functions

Macro-evolution

Increasing diversity within a population, eventually leading to entirely new species

Punctuated equilibrium

The theory that evolution occurs in very short spurts followed by long periods of no change

Vestigial

A non-functional remnant of anatomy in an organism