Saturday, April 27, 2013

Obstacles to transition from water to land

- 1- Weight-bearing: Sea-dwelling creatures have no problem in
bearing their own weight in the sea. However, most land-dwelling
creatures consume 40 percent of their energy just in carrying their
bodies around. The fish's bones are not linked to the backbone.
Therefore they can't take on a load-bearing function. Land-dwelling
creatures'bones, in contrast, are directly connected to thebackbone.
For this reason, the claim that these fins slowly developed into feet
is unfounded.
- 2- Heat retention: Land-dwelling creatures possess a physical
mechanism that can withstand great temperature changes. A living
organism with a body system regulated according to the constant
temperature of the sea would need to acquire a protective system to
ensure minimum harm from thetemperature changes onland. It is
preposterous to claim that fish acquired such a system by random
mutations as soon as they stepped onto land.
- 3- Water: Essential to metabolism, water needs to be used
economically due to its relative scarcity on land. For instance, the
skin hasto be able to permit a certain amount of water loss, while
also preventing excessive evaporation. That is whyland-dwelling
creatures experience thirst, something that sea-dwelling creatures do
not do. For this reason, the skin of sea-dwelling animals is not
suitable for a nonaquatic habitat.
- 4- Kidneys: Sea-dwelling organisms discharge waste materials,
especially ammonia, by means of their aquatic environment: In
freshwater fish, most of the nitrogenous wastes (including large
amounts of ammonia, NH3) leave by diffusion out of the gills. The
kidney is mostly a devicefor maintaining water balance in the animal,
rather than an organ of excretion. Therefore, in order for the passage
from water to land to have occurred, living things without a kidney
would have had to develop a kidney system all at once.
- 5- Respiratory system: Fish "breathe" by taking in oxygen
dissolved in water that they pass through their gills. They cannot
live more than a few minutes out of water. In order to survive on
land, they would have to acquire a perfect lung system all ofa sudden.
- The Impasse of transition from Land to Air
- There are various structural differences between birds and
reptiles, one of which concerns bone structure.Due to their bulky
natures, dinosaurs-the ancestors of birds according to
evolutionists-had thick, solid bones. Birds, in contrast, whether
living or extinct, have hollow bones that are very light,as they must
be in order for flight to take place. Reptiles have the
slowestmetabolic structure in the animal kingdom. Birds, on the other
hand,are at the opposite end of the metabolic spectrum. For instance,
the body temperature ofa sparrow can rise to as much as 48°C due to
its fast metabolism. On the other hand, reptiles lack the ability to
regulate their body temperature. Instead, they expose their bodies to
sunlight in order to warm up. Putsimply, reptiles consume the least
energy of all animals and birds the most. In land-dwelling creatures,
air flow is bidirectional. Upon inhaling, the air travels through the
passages in the lungs (bronchial tubes), ending in tiny airsacs
(alveoli). The exchange of oxygen andcarbon dioxide takes place here.
Then, upon exhaling, this used air makes its way back and finds its
way out of the lung by the same route.eptiles have a diaphragm-type
respiratory system, whereas birds have an abdominal air sac
systeminstead of a diaphragm.
John Ruben, an acknowledged authorityin the field of respiratory
physiology, observes in the following passage: The earliest stages in
the derivation of the avian abdominal air sac systemfrom a
diaphragm-ventilating ancestor would have necessitatedselection for a
diaphragmatic hernia in taxa transitional between theropods and birds.
Such a debilitatingcondition would have immediately compromised the
entire pulmonary ventilatory apparatus and seems unlikely to have been
of any selective advantage.
Reptile bodies are covered with scales, and those of birds with
feathers. The hypothesis that bird feathers evolved from reptile
scales is completely unfounded, and is indeed disproved by the fossil
record, as the evolutionary paleontologist Barbara Stahl admits: How
[feathers] arose initially, presumably from reptilesscales, defies
analysis... Itseems, from the complexconstruction of feathers, that
their evolution fromreptilian scales would have required an immense
period of time and involved a series of intermediate structures. So
far, the fossil record does not bear out that supposition.
Larry Martin, a specialist on ancient birds from the University of
Kansas, also opposes the theory that birds are descendedfrom
dinosaurs. Discussing the contradiction that evolution falls into on
the subject, he states:
To tell you the truth, if I had to support the dinosaur origin of
birds with those characters, I'd be embarrassed everytime I had to get
up and talk about it.
- The Impasse of Evolution of Reptile to Mammal
- Mammals are warm-blooded animals (this means they can generate
their own heatand maintain it at a steady level), they give live
birth, they suckle their young, and their bodies are covered in fur or
hair. Reptiles, on the other hand, are cold-blooded (i.e., they cannot
generate heat, and their body temperature changes according to the
external temperature), they lay eggs, they do not suckle their young,
and their bodies are covered in scales.Mammal jaws consist of only one
mandibular bone containing the teeth. In reptiles, there are three
little bones on both sidesof the mandible.
- All mammals have three bones in their middle ear (hammer, anvil,
and stirrup). Reptiles have but a single bone in the middle ear.
Furthermore,when mammals suddenly made their appearance, they were
already very different from each other. Such dissimilar animals as
bats, horses, mice, and whales are all mammals, and they all emerged
during the same geological period. Establishing an evolutionary
relationship among them is impossible even by the broadest stretch of
the imagination. The evolutionist zoologist R. Eric Lombard makes this
point in an article that appeared in the leading journal Evolution :
- Those searching for specific information useful in constructing
phylogenies of mammalian taxa will be disappointed.
Roger Lewin,
"The transition to the first mammal, ... is still anenigma." - -
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