Biogeography Flashcards

Flashcards on biogeography, morphological divergence, comparative anatomy and other related topics.

Morphological Divergence

Development of different structural characteristics in organisms with the same ancestor due to different environments.

Morphological Divergence

Determines relatedness of two organisms by comparing internal and external structures.

Comparative Anatomy

Comparison of structures/anatomy to understand evolutionary relationships.

Homologous Structures

Structures derived from a common ancestor but evolved in different environments.

Homologous Structures

Similarity in structure, position on body, and embryonic development, even if superficially different and not performing the same function.

Pentadactyl Limb

Five-fingered/toed limb, modified to adapt for use in different habitats.

Divergence of Form/Structure and Function

Adaptation of form/structure and function of homologous structures to meet needs of different functions/environments.

Adaptive Radiation

Descendants fill a wide variety of habitats through divergent evolution.

Analogous Structures

Similar structures in different organisms that evolved in similar environments without a common ancestor.

Analogous Structures Examples

Structures that serve the same/similar purpose, like wings in bats and insects.

Embryonic Development

Similarities in early stages implying a common ancestor in vertebrates.

Vestigial Organs

Structures/organs that seem to serve no use but are often homologous to other species where the structure/organ is useful.

Biosphere

Whole Earth surface, all parts occupied by biotic factors, including land, water, and atmosphere.

Pangaea

Giant continent that was connected before continental drift.

Biodropical Regions

Divisions of the biosphere, mainly land-based, inhabited by distinctive species (fauna and flora).

Terrestrial Biogeographical Regions

Near Neartic (North America). Eurasia (Europe, Asia, North Africa), South America, Africa (includes Madagascar), Australasia (includes New Zealand), Indomalaysian (South Asia plus all islands), Oceanic (islands North of Australia), and Antarctic.

Biogeography

Study of past and present distribution of world's many species, combining info/evidence from ecology, evolution, paleontology, and climatology.

Alfred Wallace

Founder of modern science of biogeography.

Dispersal

Movement of a population away from its point of origin.

Evolution

Change in the genetic composition of a population.

Biogeographical Distribution of a Species

Pattern of plant and animal distribution explained by Darwin.

Darwin's Explanation of Species Distribution

Each species originates from a single center of origin of the ancestral species and disperses from there.

Genotype

Genetic makeup or structure and arrangement of genes.

Phenotype

How genes are physically expressed or what characteristics are shown.

Darwin's Finches

Led to new species because species adapted to survive in various available niches on the islands.

Development of Different Species

Development of different species from a common ancestral species through microevolution, phenotype variation, and natural selection.

Continuous Variation

Phenotype characteristics that exhibit a range and are controlled by many genes.

Microevolution

Small changes within a species caused by mutations and variation in genetics.

Speciation

Formation of new species.

Phylogeny

Evolutionary history of a species/genus/group.

Geographic Speciation

Population becomes separated due to geographic isolation, leading to new species.

Gene Flow

Exchange of genes via sexual reproduction.

Geographic Speciation

Same as allopatric speciation.

Reproductive Isolation

Prevents two or more populations from exchanging genes, even without geographic isolation.

Macroevolution

Change above the species level, leading to more highly developed taxa of organisms over geological time.

Trends in Evolution

Gathered trends are shown, Evidence to support occurrence of macroevolution is study of fossil records homologies vestibular structures equals redundant organs, comparative anatomy, biogeography, molecular evolution equals mutations, biochemical similarities, comparative embryology, convergent evolution.

Adaptive Radiation

Have common ancestors and evolve in different environments to fill different niches/environments.

Divergent Evolution

Often occurs when closely related species diversify to new habitats.

Convergent Evolution

Takes place when species of different ancestry begin to share similar traits because of a shared environment or other selection pressures.

Parallel Evolution

When two species evolve independently of each other, maintaining the same level of similarities.