Phylogeny explains why some adaptation is less than perfect. From where it is, there are always some possibilities which a particular species can never get to. This is because all stages in evolution must be viable, else extinction occurs.
Another reason is that not all traits of a species can be maximised at the same time. Increase in armour, for example, is bound to slow down movement. Teeth which are best for vegetation are much less good for meat. The final result is a set of traits, most of which are sub-optimal.
Earlier phylogenetic stages and (pre-) conditions which persist often determine the form of more modern characteristics. For instance, the vertebrate eye (including the human eye) has a blind spot, whereas octopus eyes do not. Once the vertebrate eye had evolved, the only way it could improve was to minimise the effect of the blind spot. We don't notice it ordinarily, because with binocular vision what one eye misses, the other fills in.
All instances of behaviour require an explanation at each of these four levels. For example, the function of eating is to acquire nutrients (which ultimately aids survival and reproduction), but the immediate cause of eating is hunger (causation). Hunger and eating are evolutionarily ancient and are found in many species (evolutionary history), and develop early within an organism's lifespan (development). It is easy to confuse such questions – for example to argue that people eat because they're hungry and not to acquire nutrients – without realizing that the reason people experience hunger (causation) is because it causes them to acquire nutrients (function).
Henry III of England
Henry III (1 October 1207–16 November 1272) became King of England in 1216 when he was 9 years old, after the early death of his father King John. He would end up ruling as king for 56 years (though he would only effectively rule for around 45 due to his youth in the first years). He would be married to Eleanor of Provence, who bore him 5 children, for 36 years. During his long reign, Henry's kingdom would experience relative peace and prosperity until he began having trouble with his barons (particularly Simon de Montfort) due to his high handed governing style, which compelled the Barons to impose the Provisions of Oxford limiting royal power in 1258.
The king's breaking of this agreement with the barons a few years later would lead to a civil war called the Baron's war which pitched the royal family against the rebel barons for 3 years (1264-1267), culminating in De Montfort's death at the unusually bloody Battle of Evesham in 1265 and the royal family being able to sweep up the remnants of the opposition by 1267. However, Henry's most visible mark on history would be due to his interest in architecture and decoration: which made him redevelop certain aspects of Westminster Abbey, improve the Tower of London's defenses (while keeping exotic animals from africa and the artic such as lions, an elephant and a polar bear in it). He would even preside over the reburial of his personal hero Edward the Confessor at the consecration of Westminster Abbey in 1269, which was seen as the greatest personal triumph of his reign. Soon after the consecration of his abbey, the aging Henry would began to see a sharp decline in his health, eventually dying in 1272 at the fairly advanced age of 65, with his eldest son Prince Edward ascending the throne as King Edward I of England. The new king would have his late father reburied in 1290 in Westminster Abbey, where he has laid till modern historians discovered his tomb, which revealed that Henry III was about 5’ 6” tall and had a drooping left eyelid.
Edward I of England
Edward I (17 June 1239–7 July 1307), also "Longshanks" (meaning 'long legs') and the "Hammer of the Scots", was a Plantagenet King of England. He became king on 21 November 1272, until his death in 1307. His mother was Queen Eleanor of Provence and his father was King Henry III of England. As a younger man, Edward fought against Simon de Montfort in defence of his father's crown. He went on a Crusade, and his father died as Edward was on his way back. As a ruler, he improved the laws and made Parliament regular, and more important. He conquered Wales, and subdued the Welsh by brutal policies. He was determined to control Scotland through puppet kings and just managed to do it during his lifetime. He expelled the Jewish people from England.
Edward was born at Westminster in June 1239 to the English King Henry III and his wife, the French noblewoman and English Queen Eleanor of Provence. The baby Edward and was named after an earlier king, Edward the Confessor, who happened to be a personal hero of his father King Henry The boy Edward would have a good education, being taught in Latin and French which were the most used languages in Europe at the time.
In 1254, English fears of a Castilian invasion of the English province of Gascony induced Edward's father to arrange a marriage between his 15-year-old son and the 13 year-old Eleanor, the half-sister of King Alfonso X of Castile.
Eleanor and Edward were married on 1 November 1254 in Castile. As part of the marriage agreement, the young prince got grants of land worth 15,000 marks a year. Though the endowments King Henry made were sizable, they offered Edward little independence. He had received Gascony as early as 1249, but Simon de Montfort, 6th Earl of Leicester, as royal lieutenant, drew the income. In practice, Edward derived neither authority nor revenue from this province. The grant he received in 1254 included most of Ireland, and much land in Wales and England, including the earldom of Chester, but the king kept control over the land, particularly in Ireland, so Edward's power was limited there as well, and the king got most of the income from those lands.
The years 1264–1267 saw the conflict known as the Second Barons' War, in which baronial forces led by Simon de Montfort fought against those who remained loyal to the king. The first scene of battle was the city of Gloucester, which Edward, now a young man who could participate in battles, managed to retake from the enemy. When Robert de Ferrers, Earl of Derby, came to the assistance of the rebels, Edward negotiated a truce with the earl, the terms of which he later broke. Edward then captured Northampton from de Montfort's son, also Simon. The baronial and royalist forces finally met at the Battle of Lewes, on 14 May 1264. Edward, commanding the right wing, performed well, and soon defeated the London contingent of de Montfort's forces. Unwisely, however, he followed the scattered enemy in pursuit, and on his return found the rest of the royal army defeated. By the agreement known as the Mise of Lewes, Edward and his cousin Henry of Almain were given up as prisoners to de Montfort.
Edward remained in captivity until March, and even after his release he was kept under strict surveillance. Meanwhile, de Montfort used his victory to set up a "de facto" government. He even summoned the Parliament of 1265, known as de Montfort's Parliament.
Then, on 28 May 1265, Edward managed to escape his custodians and joined up with the Earl of Gloucester, who had recently defected to the king's side. Montfort's support was now dwindling, and Edward retook Worcester and Gloucester with relatively little effort. Meanwhile, Montfort had made an alliance with Llywelyn and started moving east to join forces with his son Simon.
Edward managed to make a surprise attack at Kenilworth Castle, before moving on to cut off the earl of Leicester.
The two forces then met at the second great encounter of the Barons' War the Battle of Evesham, on 4 August 1265. Montfort stood little chance against the superior royal forces, and after his defeat he was killed and mutilated on the field.