from a Devonian reef, now fossilized in Pennsylvania. She encounters many specie
ID: 202871 • Letter: F
Question
from a Devonian reef, now fossilized in Pennsylvania. She encounters many species that are new to science. a) Which species concept would be most expedient and effective, in the process of collecting, naming, and describing what she finds? b) Go online and research. Give at least three examples of actual species that were present in the Devonian period. What is the point, if there IS any point, to naming and describing species that went extinct millions of years ago? c) Research reefs. Give some ideas about why reef communities, in times during the history of the Earth when they existed, have such high diversity? What happened to the Devonian reefs? d) Research and describe threats to contemporary coral reef systems. List, and describe, the major threats to these systems resulting from climate change, human disturbance, ocean factors. acidification, and other 2. (two points) A researcher is studying the mating calls of a widespread species of syrphid fly. She discovers that males differ greatly in their banding patterns, but females are essentially identical. In laboratory crosses, females do not discriminate among males with different banding patterns, BUT, when they mate with males that do not have a banding pattern typical of the area they came from, these crosses produce eggs that do not hatch. a) Are these flies a single species, or perhaps a species complex? Is there an isolation mechanism? Explain? b) Go online and research. Give at least two examples of species complexes composed of morphologically similar microspecies or cryptic species. e) What is a syrphid fly? Research a few species and describe the ecological niches they occupyExplanation / Answer
a)The species concept that would be most effective would be morphological species concept. Since the species are new to science and the gene flow is unknown it would be most effective to collect, name, and characterize the species based on body shape and other structural features. When more time is allotted the researcher can try finding a similar ancestor to the new species, evolutionary species concept, or characterize through interbreeding using biological species concept.
b)The Devonian period, also referred to as the Age of Fishes is said to haveoccurred 358 to 416 million years ago (Bagley). Three species of theDevonian period are ammonoidea, crinoid and sarcoptergii. The ammonoidsresembled an octopus of squid and had a large spiraled shell (Ammonoidea).Crinoids resemble a flower but their “petals” have the hallmarks of feathers ortentacles. Crinoids used their stem for locomotion or to attach themselves to the sea floor. The arms were used to absorb and transport nutrients down tothe mouth (Crinoids). Finally, the sarcoptergii or lobe- finned fish are a bony ish with flesh like fins. These fins are said to have evolved into legs and alltetrapods are decedents of sarcopterygians (Sarcoptergii). Towards the end ofthe Devonian period it is recorded that the first four limbed vertebrates walkedon land (Bagley).Naming and classifying species, even those that have gone extinct isvaluable for further research in evolution. It was recorded that in the Devonianperiod the first vertebrates walked on land better known as tetrapods andhumans are considered tetrapods (Bagley). Characterizing species allows forresearchers to track gene flow and this data can be used in the field ofmedicine for disease or genetic research.
c)Reefs are an underwater ecosystem thrive best is shallow, warm and sunnywaters. Reefs have become a home for many fish, plankton, and algae. Thedirect sunlight that hits many of these reefs is an energy source for some of thespecies. The many species that live on and around reefs depend on theecosystem of the reefs and species around it for nutrients. The abundantsource of nutrients and protection is one of the reasons reefs, throughouthistory, have seen great biodiversity (Reef Ecosystem). The Devonian reefswere greatly affected by the extinction of the Devonian period along withother marine life (Bagley).
d) OCEAN ACIDIFICATION
ocean acidification occurs as atmospheric CO2 increases and the ocean absorbs it. earlier the ocean’s pH was relatively stable. but now, it’s dropping because of the reactions between seawater and CO2, and corals are now lacking carbonate ions and also as the level of dissolved CO2 in the ocean is rising, it is damaging coral skeletons, making them break and crumble.
CORAL BLEACHING
the ocean is getting warmer Corals are extremely sensitive to small temperature changes. they can react to temperature increases by expelling their symbiotic algae, known as zooxanthellae.so when they leave, the coral is at risk of dying and it obtains a characteristic pale colour, defining the expression “bleaching.”
OVERFISHING
fishers use destructive practices like adding chemicals to the water to stun fish, deep water trawling or using explosives to quickly startle fish to the surface of the water. These practices damage the coral. crab and lobster traps can also damage reefs by crashing nearby in the current and entangling coral in their ropes.
DEVELOPMENT
Coastlines tend to make popular places for development. they were ideal for trade and other activities Now, coastlines have become one of the most popular places in the world to live for coral, development is bad because it increases pressures on already fragile reefs.
RADIATION
Coral is not prepared for ozone depletion. As the Earth’s ozone has become thin corals are showing signs of damage caused by UV exposure;
MINING
coral is removed for use in making roads, paths and various other products.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.