Evolutionary evidence showcases the importance of ancient species that evolved through million years ago and still existed at present time. Environmental changes, geographic movement and plate tectonic changes can affect the evolutionary process of a certain species morphologically for survival. The paper signifies the lineage of certain endemic gastropod species in Lake Malawi. The authors try to trace the evolutionary origin of this particular species predicting that this is an endemic species of the certain lake.
Evolutionary history of gastropod species in Lake Malawi
Environmental conditions are one of the contributory factors that affect the morphology of the gastropod Lanistes. Two species are said to be endemic of Malawi Lake these are the Lanistes ovum and Lanistes ellipticus. Phylogenetic analysis shows that these two species did not cluster to any species found at the vicinity of Lake Malawi. The spatial vicinity of the nearby lakes was also examined for the presence of this gastropod, through morphological analysis. And it shows similarity but not genetically using mitochondrial COI gene as a biomarker.
Theoretically, a possible potential transition since at Lake Kazuni at around 50 km from Lake Malawi has Lanistes ovum complexes. Fossil record will always admit the origin of the certain species through time. The authors give importance on lineages as basis for taxonomic purposes and evolutionary processes. In which molecular time is relevant in shifting the morphogenetic properties of a certain species.
Indeed, Lake Malawi consists of endemic species to the entire Malawi rift rather than endemic to the lake proper. It also signifies phylogenetic relationship within genus through parallel evolution. And provides evidence that gastropod Lanistes species are not restricted in certain area but are present throughout Malawi rift.
Source: Prepared by Joan Tura from Proceedings Biology Science
2009 Aug 7; 276(1668): 2837–2846