Answer:
The North American Cactus and African Euphorbia species originated from two different, but similar plants.
Explanation:
These plants were the typical herbaceous species of the early Earth, characterised by their slim stems and large, wide leaves. However, their evolutionary paths began to change with the separation of the early supercontinents, Pangaea and Gondwana. As variations in the climate caused the development of harsh, arid, desert environments, both plant families experienced convergent evolution in order to adapt and survive. Cacti and Euphorbias both converged on similar forms and metabolisms after prolonged exposure to corresponding environments, due to the fact that similar biomes can require the same adaptations.
<em><u>Adaptations
</u></em>
- Branching Stems Covered In Longitudinal Ribs
- Smaller leaves And Short Spines
- Spreading, Shallow, Fibrous Root System
- Water Storage System - Succulent Stems
- Crassulacean Acid Metabolism
<em>Hope u will understand this</em>
Answer:
Answered below.
Explanation:
The fossil records are beneficial in giving us. wide range of knowledge about fossils but sometimes these records are flawed, in that they are incomplete or misleading.
Many of the fossil records available are incomplete because some animals tend to decay within a short period of time due to their soft tissue. Also some are destroyed due to the movement of tectonic plates over time.
Another flaw scientists encounter is that there are no fossils which illustrate or represent the orderly transition from one organism to another. Fossils generally do not support the Darwinian theory of evolution as no evidence is found of ordered, sequential transition from simple to complex life forms as postulated.
These flaws are significant because they influence our knowledge and understanding of life forms and evolution.
If we take a look at the phylogenetic tree of bears presented in the picture above, we can see that the branch number one is the common ancestor to all living bear species, which means that the whole group has a uniform origin. and the
phylogenetic tree has a root. Therefore, the group is monophyletic, not <span>polyphyletic ( meaning that the whole group has the same origin) and not paraphyletic ( there is no group that has been excluded from the tree).</span>