Cummins (1980;1981;1996) theorized that there are two kinds of English proficiency that ESL students must learn. The first is basic interpersonal conversational skills (BICS) that ESL students need when they carry on face-to-face conversation in social settings. BICS English is characterized as context-embedded since contextual cues are available to both speaker and listener involved in the conversation, and it is cognitively undemanding. As the vignette illustrates, ESL students can easily recount orally what happened to them personally without difficulty once they attain fluency. According to Cummins (1980), it takes only 2 to 3 years for ESL students to attain BICS English. In other words, BICS English is easy to learn, and can be attained in a rather in a short period of time.
The other proficiency is cognitive academic language proficiency (CALP). CALP English is characterized as context-reduced, as is found in written texts in content areas such as math, science, and social studies. Due to its decontextualized nature, ESL students struggle to comprehend what they read and to express what they know in writing. CALP English used in context-reduced academic learning demands high cognition on the part of the ESL student. In addition, Cummins reports that it takes 5 to 7 years for ESL students to be proficient in CALP English. Unlike BICS learning, CALP learning is a long-term undertaking. Collier (1987, 1989; Collier & Thomas, 1989) suggests that it can take up to 10 years for ESL students to reach grade-level CALP English depending on the kind of English instruction they receive. Collier & Thomas (1989) report that the ESL students who were taught in pull-out ESL settings took the longest time to reach grade level. What Cummins' BICS and CALP signify for ESL education is that, in order for ESL students to read and comprehend content area textbooks and perform cognitively demanding tasks, such as writing research papers, participating in debates, and presenting research papers, they need CALP English that takes them beyond that of BICS English.
Chimps and orangutans have distinct cultures and ways of transmitting knowledge, usually confined to observation. They have regional variations in tool use, and orangutans can display startling intelligence in captivity that is not witnessed in the wild, which may be like country bumpkins moving to the city where they can develop their intellects or get a chance to use them. Chimps can negotiate, deceive, hunt in ranked groups, learn sign language, use more than one tool in a process, problem-solve, and engage in other human-like activities. Developmentally, a chimp is ahead of a human until about age two, and chimps can also express empathy. Research has suggested that imitation (performing somebody else’s actions) and empathy (feeling what somebody else feels) are related neurologically. Humans, however, are far better than chimps in their social-cognitive skills, which brings in the "theory of mind," which is guessing what others are thinking. This is suspected to be the key developmental trait that set humans apart from their cousins.
There are three primary survival requirements for any species: obtain nutrients (always primarily energy), avoid becoming nutrients, and perform those first two tasks long enough to produce offspring. If those requirements are not met, the species will go extinct. The eating instinct outranks the sex drive, but avoiding becoming food is where the most energetic behaviors can usually be found. Primal survival instincts take over during the . In humans, that to enable the body to perform feats of physical survival. That is when pumps. All evolutionary adaptations studied by scientists always have those three primary requirements girding the explanatory framework.
The rise of humans was dependent on numerous factors, but the most important may have been the ability to increase humanity’s collective knowledge. If each invention during human history had to be continually reinvented from scratch, there would not be people today. The cultural transmission of innovations was critical for growing humanity’s collective technology, skills, and intelligence. Striking stones to fashion tools was new on Earth, and it was likely invented , and then proliferated as others learned the skill. The pattern of proliferation of stone tool culture in Africa supports that idea.
Creationist critiques of the evolutionary corpus, which all-too-often attempt to portray the as literally true, often use the eye as evidence of their Creationist notions. The eye is too complex and function-specific to be some kind of evolutionary development, so goes Creationist reasoning. Even Darwin confessed to the problems that eyes posed for his theory of natural selection, stating that the notion of eyes' being the product of seems “absurd.” However, the appears pretty clear to today’s scientists. Below is the current conception of the evolutionary path of eyes. (Source: Wikimedia Commons)
Once animals arrived on the evolutionary scene and filled most possible niches, new biological foundations could not be built, with superstructures built atop them, and hope to compete for resources that were already being consumed in the food chains. Developing the original animal body plans took millions of years. There were many other possible body plans that have been developed in the early days of animals, which might have worked wonderfully, but those chosen ones worked well enough for survival and reproduction, and once chosen, there was no going back. There really could not be, unless animal life was wiped out and could start over, as they are the last common ancestors of animals (and eliminating all animal life would lead to great plant extinctions for starters, such as ). The biological commitments to those basic modes of existence had their own inertia, and it starts at the root, with the DNA.
Imagine a family having a custom home built and, after it was built, they decided that they wanted a basement, four extra stories, central gas heating rather than baseboard electric heating, and a swimming pool on the third floor. It would not be feasible to renovate the home to give it those new features, especially if the family was already living in it. They would need to build a new house from scratch, with a new foundation, and they would have to find a temporary home during the construction period. But an animal has to live in its body all the time. There is no way to redesign and rebuild an animal’s foundation while it lives in its body, and the biological superstructure built on the foundation was designed for foundation. A new superstructure would also have to be designed and built on the new foundation. A six-chambered heart, for instance, could not just be invented and put into a human chest and work, or a second brain, or a third arm. The kinds of changes that feasible have to adhere to the basic structural and biochemical foundations that the phyla represent.
Eyes began with that captured photons that through chemical cycles in a new kind of specialized cell: the nerve cell. Neurons are energy hogs and “high-tension electric lines” in animals. Human brain tissue uses ten times the energy that non-organ tissues elsewhere in the body do. The first eyes probably only detected light, and perhaps even infrared light, so that from life-giving/destroying volcanic vents, for instance. Hydrothermal vent shrimp today , which can be likened to naked retinas. The development of an eye with a lens was not a great evolutionary leap from rudimentary eyes, and a recent calculation shows how eyes with lenses could have developed from scratch in about a half-million years of evolution. may have had the first precursors to eyes. Once the eye evolved, its benefit was overwhelmingly obvious, and virtually all animals that live where vision would help them have eyes. Animals that adopted subterranean existences . It is thought today that the development of eyes was a key innovation in the arms race that would soon characterize the eon of animals, and might have even triggered it. The gene is common to all animals with eyes. As , that gene supports the widely accepted idea that . The purpose of all senses is to detect environmental information, which is in turn processed by the brain. Even brainless plants can detect light and modify their behavior, such as .
An important evolutionary principle is organisms' developing a new feature for one purpose and then using that feature for other purposes as the opportunity arose. As complex life evolved in the newly oxygenated seafloors, several immediate survival needs had to be addressed. To revisit the , if an oxygen-dependent animal did not have access to oxygen, it meant immediate death. Obtaining oxygen would have been the salient requirement for early complex life that adopted aerobic respiration , which is how nearly all animals today respire. While animals in low-oxygen environments have adapted to other ways of respiring (or perhaps in the first place), they are all sluggish creatures and would have quickly lost in the coming arms race. , which is a critical connective tissue in animals, requires oxygen for its synthesis, and was one of numerous oxygen-dependencies that animals quickly adopted during the Cambrian Explosion.
consist of body plans, which scientists have used to classify all life forms, and all significant animal phyla had appeared by the Cambrian Period’s end. The Cambrian Explosion has been difficult to explain and there is still great controversy and many unanswered questions, and it has also been difficult to explain why significant change stopped the explosion. Once the basic body plans appeared and biomes were filled, new plans never appeared again. Why did all fundamental change stop? The emerging view is the same for why complex life with and never changed since then. Not only could innovation confer great benefits, but , further travel along the developmental path made it continually less feasible to backtrack, start over, and take another path, or choose a fundamentally different path. The history of life’s choices was reflected in organisms in several ways, and the source of that inertia began to be understood when biology and chemistry at the cellular and subcellular levels were investigated, particularly after DNA was sequenced and studied. The fact that have not significantly changed in several hundred million years points to the issue. Hox genes have not changed because they control key developmental steps in embryonic development. Not only do Hox genes work, there are no practical ways to significantly change them, as they lay the animal’s structural foundation. Hox genes are called regulatory genes, and the nature of seems to be why animals have not fundamentally changed since the Cambrian Explosion.