which form of classification groups animals based on their phylogenetic similarities?
a) order
b) cladistics
c) linnaeus
d) systematic
Since this is not my area of expertise, I searched Google under the key words "classifying animals" to get these possible sources:
http://www.google.com/search?client=safari&rls=en&q=classifying+animals&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
The correct answer is b) cladistics.
Cladistics is a form of classification that groups animals based on their phylogenetic similarities. Phylogenetics is the study of the evolutionary history and relationships among organisms. In cladistics, organisms that share a common ancestor are placed together in a group called a clade. Cladistics uses shared derived characteristics, called synapomorphies, to define these clades.
To arrive at a cladistic classification, scientists typically use a method called cladogram construction. Here's a step-by-step process to better understand how cladistics works:
1. Collect data: The first step in cladistics involves gathering data on the morphological, anatomical, or molecular characteristics of the organisms being studied.
2. Character selection: From the collected data, researchers choose specific characteristics, known as characters, that are informative for determining evolutionary relationships. These characters can be shared physical features, genetic sequences, or behavioral traits.
3. Character state determination: Each character is analyzed to determine its presence or absence (or alternative states) in the organisms being studied. These states are then coded as binary data (0 = absent, 1 = present) for analysis.
4. Character matrix creation: The binary data for each character is organized into a matrix, with organisms represented in rows and characters in columns.
5. Similarity analysis: Using various statistical algorithms (e.g., Maximum Parsimony, Maximum Likelihood, Bayesian Inference), the matrix is analyzed to determine the most likely evolutionary relationships between the organisms. These algorithms evaluate the hierarchical grouping of organisms based on the similarities and differences observed in their character states.
6. Cladogram construction: The analysis results are used to build a cladogram, which is a branching diagram that represents the evolutionary relationships among the organisms. The cladogram shows the order in which organisms shared common ancestors and the relative amount of shared derived characteristics (synapomorphies).
By following the steps outlined above, scientists can use cladistics as a powerful tool to classify organisms based on their evolutionary relationships and genetic similarities. This method allows for a more accurate understanding of the natural history and biodiversity of living organisms.