4.3 Phenotypic changes that appeared without being selected As well as these behavioural changes, many of the selected foxes had unusual white markings (Figures 13c and d). The first colour change that the Russian investigators noted in their foxes was a white ‘star’ on the forehead similar to that of other domesticated mammals (Author(s):
Introduction Most contemporary evolutionary biologists study evolution experimentally using laboratory organisms such as Drosophila or natural systems in the wild. However, 18th and 19th century evolutionary biologists, including Darwin, emphasised the similarities between natural evolution and artificial ‘ improvement’ of livestock under domestication. They believed that studying domesticated animals and plants could illuminate the mechanisms of natural evolution. Indeed, Chapter 1 of On th
2 Inside the Sun To account for its brightness and activity, the Sun must contain a power source. However, the nature of that power source was a great puzzle in the nineteenth and early twentieth centuries. Fossil records and ideas about evolution were beginning to provide firm evidence that the Earth must be at least hundreds of millions of years old, rather than thousands of years as was previously thought, and the Sun must be at least as old as the Earth. The only fuels known at the time were coal, wood, o
3 Introducing the primates One group of accomplished tree dwellers are the primates – a term you perhaps think of as synonymous with monkeys and apes. Monkeys and some apes display some of the most striking adaptations to tree-living. 250 or so species of primate exist today; most taxonomists group them into 13 families. All share a lengthy list of defining features, mostly related to the following broad categories: Limbs and locomotion. The hands (and often the
2.5 Tree squirrels Coevolution also underpins the relationship between many tree squirrels and the trees that house them. The creation of food caches as a ‘winter-larder’ is mutually beneficial, partly because squirrels are sufficiently profligate in their habits to ensure that many stores are overlooked. Stealing by neighbours is so common that such over-provision may be essential – it's not through forgetfulness or lack of skill; grey squirrels appear able to detect nuts buried as deep as 30 cm below th
Acknowledgements Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit: The content acknowl
Senses Being an effective predator requires efficient sense organs. Prey often has to be located from a considerable distance and good spatial awareness comes into play during the moments of capture. The precise mix of sensory inputs used varies a good deal, just as it does in other animal groups; many rely on good eyesight for hunting; for others, smell and/or hearing are especially important. And you'll know from the TV programme (for example, in what was said about the importance of smell in brow
10 Living in herds Wildebeest are only one of the species of plant predator that live in herds. Many others do too. Watch the the TV programme from 30.48–47.32 and read LoM p. 109. Identify and write down (a) a couple of advantages and 5.1.4 Getting agreement with the no-monopole law Substituting Equation 7.23 into the no-monopole law gives immediate agreement because The no-monopole law is analogous to Gauss's law in empty space, and it leads to a similar conclusion: the magnetic wave must be transverse. This has already been established using Farada 5.1.2 Getting agreement with Gauss's law Substituting the assumed form of the electric field (Equation 7.20) into the empty-space version of Gauss's law (Equation 7.16) gives The first two partial derivatives are equal to zero because f does not depend on x or y. So we obtain 3.1 Graphs Information is everywhere these days – in the form of images, written records, tables and graphs. In this part of the unit we want you to realise how useful graphs can be to analyse numerical information, and to show you some techniques that can help you decide how reliable this numerical information is. It's often difficult to spot a trend or a relationship in a long list of numbers. Because the human mind is highly adapted to recognising visual patterns, it is often much easier to u 1.3 Marking decimals on a scale
Figure 2 shows a picture of a ruler. The major units are marked in centimetres (1 to 11 cm), whilst the intervals between the centimetres have each been split into ten equal, smaller units. These minor units are therefore tenths of a centimetre, commonly known as ‘millimetres’. (There are 10 millimetres in 1 centimetre 1.2.1 Study Note 1 Simple rules for dealing with orders of magnitude and decimal points in decimal numbers: values ten times bigger than the order of magnitude you are looking at go to the left, ten times smaller go to the right, and less than 1 to the right of the decimal point. Note: in many European countries, a comma is used instead of a decimal point. For instance in France and Germany two and a half (in other words 2.5) can be written as 2,5. This is important to bear in mind, for example, if 1.2 Decimal points Suppose you have less than one of any particular unit: how would you represent that using the decimal system? Well, we've already seen that decimal numbers rely on a positional system, in which values get smaller by factors of ten as you read from left to right. If we continue doing this, then the number to the right of a single unit represents tenths of that unit. A decimal point is then used to mark the boundary between the whole units and tenths of that unit. For instanc 1.1 Introducing the decimal system of numbers Many different systems for writing numbers have been developed over the history of humankind. The easiest way of counting small numbers is to use your fingers, and for this reason many numerical systems, such as the decimal system, are based around the number ten. But what happens when you run out of fingers to count on? Numbering systems get round this problem by using a system of scale in which many small units are represented by a single larger unit, and many of these la Learning outcomes By the end of this unit you should be able to: understand the decimal system of numbering (hundreds, tens, units); explain the best way to write down decimal numbers and associated units of measurement in the healthcare workplace, in a manner that avoids confusion; understand the concepts of discrete and continuous variables and the best types of graphs used to represent these data; analyse, construct and extract information from grap Introduction This sample of S110 material is taken from Module 2, entitled Using numbers and handling data. As you read the material, bear in mind that it is taken from a work-based course, designed for those who are employed in the health services, perhaps as a paramedic or as operating theatre staff. If you were a student on the course, you would have an OU tutor to help you, plus a work-based mentor supplied by the employer – normally the NHS. The aim is to use the workplace as a teaching aren Acknowledgements The content acknowledged below is Proprietary (see terms and conditions). This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit: 7 Unit questions Now you have completed this unit, try the following questions to test your understanding of this material. Like the Variscan Orogenic Belt, the Caledonian includes large granitic intrusions. Using the Author(s): 2.3 The study of a raindrop Most of the usable water is derived from the 1.1 × 105 km3 that falls over the land surface each year as rain, snow, sleet or hail. The collective term for all of these sources of water is precipitation. At this point, you will consider the size of the drops of water that make up clouds or rain (Figure 5).
Activity 7
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Question 19
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