1.4 KiB
1.4 KiB
G11 Pre-AP Biology Species is a group in organism that interbreed in nature and produce fertile offspring. Flawed definition though, bacteria don't sexually reproduce, and there are separate species that are able to mate and create fertile children.
Three types of species:
- Morphological Species:
- Studies shape, size, physics, structural features.
- Simple, quick.
- Most populations have variation.
- Biological Species:
- Ability to reproduce in nature and produce fertile offspring.
- Most commonly accepted definition, objective.
- Can't test on asexually reproducing, extinct, and/or physically separated organisms.
- Phylogenetic:
- Studies evolutionary history and relationships among organisms.
- Can be applied to extinct species.
- Not all evolutionary histories are known.
Species relatedness can be determined using a phylogenetic tree. Phylogenetic trees are formed using evidence.
- Anatomical Evidence:
- Studying structure and form.
- Includes size shape and other physical features.
- Physiological Evidence:
- Study of functions/processes, such as chemical and internal processes.
- Example, guinea pig's insulin is closer to humans than mice.
- DNA Evidence:
- Studying DNA sequence (bases) or amino acid sequence. DNA similarity positively correlates with relation.
In terms of evidence credibility for relatedness, DNA > physiological > anatomical.